C語言學習筆記：從入門到實戰(zhàn)

第1 章　C 語言基礎(chǔ)知識介紹
1.1　永不過時的C 語言 ............................................................................................1
1.1.1　品味C 語言這一壇老酒 ....................................................................................1
1.1.2　C 語言的發(fā)展史 .................................................................................................2
1.1.3　學習C 語言還有用嗎 ........................................................................................2
1.2　認識段C 語言程序 ....................................................................................3
1.2.1　編寫段C 語言程序 ....................................................................................3
實例1-1：段C 語言程序（定義變量并進行算數(shù)操作） ................................................. 3
1.2.2　分析C 語言程序的具體組成 ............................................................................4
1.3　如何學好C 語言 ................................................................................................6
第2 章　安裝C 語言開發(fā)工具
2.1　一步到位的Visual Studio ..................................................................................7
2.1.1　安裝Visual Studio 2017 .....................................................................................7
2.1.2　使用Visual Studio 2017 .....................................................................................9
實例2-1：使用Visual Studio 2017 運行一個C 程序 ................................................................ 9
2.2　使用DEV C 開發(fā)C 語言程序 ...................................................................12
2.2.1　安裝DEV C ..................................................................................................12
2.2.2　使用DEV C 運行一個C 語言程序 ............................................................14
2.3　使用Turbo C 3.0 開發(fā)C 語言程序 ................................................................14
2.3.1　安裝Turbo C 3.0 ...............................................................................................14
2.3.2　使用Turbo C 3.0 ...............................................................................................15
第3 章　C 語言語法基礎(chǔ)
3.1　標識符和關(guān)鍵字 ..............................................................................................16
3.1.1　標識符 ...............................................................................................................16
3.1.2　關(guān)鍵字 ...............................................................................................................17
3.2　數(shù)據(jù)類型 ..........................................................................................................19
3.3　常量和變量 ......................................................................................................20
3.3.1　常量 ...................................................................................................................20
3.3.2　變量 ...................................................................................................................21
實例3-1：計算圓的周長和面積 ............................................................................................... 23
3.4　整型數(shù)據(jù) ..........................................................................................................24
3.4.1　整型常量 ...........................................................................................................24
3.4.2　整型變量 ...........................................................................................................26
實例3-2：計算兩個整型變量的和 ........................................................................................... 27
3.5　實型數(shù)據(jù)類型 ..................................................................................................28
3.5.1　實型常量 ...........................................................................................................28
3.5.2　實型變量 ...........................................................................................................29
實例3-3：對一個很大的數(shù)和一個很小的數(shù)進行加法運算 ................................................... 29
3.6　字符型數(shù)據(jù) ......................................................................................................30
3.6.1　字符常量詳解 ...................................................................................................30
實例3-4：通過轉(zhuǎn)義字符輸出指定的文本字符 ....................................................................... 31
3.6.2　字符串常量 .......................................................................................................32
實例3-5：我喜歡的偶像是歐陽娜娜 ................................................................................... 32
3.6.3　字符變量 ...........................................................................................................33
實例3-6：將字符變量和整型變量進行相互賦值 ................................................................... 33
3.7　整型、實型和字符型數(shù)據(jù)之間的運算 ..........................................................34
3.7.1　強制轉(zhuǎn)換 ...........................................................................................................34
實例3-7：將int 類型強制轉(zhuǎn)換為double 類型 ........................................................................ 35
3.7.2　自動轉(zhuǎn)換 ...........................................................................................................35
實例3-8：計算圓的大概面積和精確面積 ............................................................................... 36
第4 章　運算符和表達式
4.1　運算符和表達式介紹 ......................................................................................37
4.2　算術(shù)運算符和算術(shù)表達式 ..............................................................................38
4.2.1　算術(shù)運算符的分類 ...........................................................................................38
4.2.2　單目運算符 .......................................................................................................39
實例4-1：使用單目運算符實現(xiàn)基本的數(shù)學運算 ................................................................... 39
4.2.3　雙目運算符 .......................................................................................................39
實例4-2：獲取任意小于1000 的正整數(shù)的個位、十位、百位和千位的數(shù)字 ..................... 40
4.3　賦值運算符和賦值表達式 ..............................................................................40
4.3.1　基本的賦值運算符 ...........................................................................................41
4.3.2　復合賦值運算符 ...............................................................................................43
4.3.3　賦值表達式 .......................................................................................................43
實例4-3：實現(xiàn)基本的賦值表達式運算處理 ........................................................................... 43
4.4　關(guān)系運算符和關(guān)系表達式 ..............................................................................44
4.4.1　關(guān)系運算符 .......................................................................................................44
4.4.2　關(guān)系表達式 .......................................................................................................44
實例4-4：比較體重 ................................................................................................................... 45
4.5　逗號運算符和逗號表達式 ..............................................................................46
4.5.1　逗號運算符 .......................................................................................................46
4.5.2　逗號表達式 .......................................................................................................46
實例4-5：使用逗號運算符實現(xiàn)數(shù)學運算 ............................................................................... 47
4.6　邏輯運算符和邏輯表達式 ..............................................................................48
4.6.1　邏輯運算符 .......................................................................................................48
4.6.2　邏輯表達式 .......................................................................................................49
實例4-6：對變量進行邏輯運算處理，并輸出運算后的結(jié)果 ............................................... 49
4.7　求字節(jié)數(shù)運算符sizeof ....................................................................................50
實例4-7：使用sizeof 運算符計算不同類型數(shù)據(jù)的字節(jié)大小 ................................................ 51
4.8　運算符的優(yōu)先級 ..............................................................................................52
第5 章　數(shù)據(jù)的輸入和輸出
5.1　語句介紹 ..........................................................................................................54
5.1.1　C 語句簡介 .......................................................................................................54
5.1.2　賦值語句 ...........................................................................................................56
5.2　C 語言內(nèi)置的數(shù)據(jù)輸入和輸出函數(shù) ...............................................................57
5.2.1　使用字符輸出函數(shù)putchar ..............................................................................58
實例5-1：使用函數(shù)putchar 輸出指定的字符 ......................................................................... 58
5.2.2　使用字符輸入函數(shù)getchar .............................................................................59
實例5-2：使用getchar 函數(shù)獲取在鍵盤中輸入的內(nèi)容.......................................................... 60
5.2.3　使用格式輸出函數(shù)printf .................................................................................60
實例5-3：使用printf 函數(shù)輸出不同格式變量a 和b 的數(shù)據(jù) ................................................ 61
實例5-4：使用printf 格式字符輸出指定格式的數(shù)據(jù) ............................................................ 62
5.2.4　使用格式輸入函數(shù)scanf ..................................................................................64
實例5-5：輸出顯示用戶輸入字符的ASCII 碼和對應的大寫字母 ....................................... 66
5.2.5　使用字符串輸出函數(shù)puts ...............................................................................67
實例5-6：使用函數(shù)puts 輸出指定的字符串 ........................................................................... 67
5.2.6　使用字符串輸入函數(shù)gets ................................................................................68
實例5-7：輸出顯示用戶的姓名和身高信息 ........................................................................... 68
第6 章　使用流程控制語句
6.1　順序結(jié)構(gòu) ..........................................................................................................69
實例6-1：計算三角形的面積 ................................................................................................... 70
6.2　選擇結(jié)構(gòu) ..........................................................................................................70
6.2.1　單分支結(jié)構(gòu)語句 ...............................................................................................71
實例6-2：從大到小排列3 個數(shù)字 ........................................................................................... 71
6.2.2　雙分支結(jié)構(gòu)語句 ...............................................................................................72
實例6-3：判斷用戶輸入內(nèi)容的格式 ....................................................................................... 72
實例6-4：判斷變量a 和b 的值是多少 ................................................................................... 74
6.2.3　使用多分支結(jié)構(gòu)語句 .......................................................................................75
實例6-5：提示用戶輸入數(shù)字，然后將用戶輸入的數(shù)字輸出。 ........................................... 77
6.2.4　條件運算符和條件表達式 ...............................................................................77
實例6-6：比較兩個數(shù)字的大小并輸出數(shù) ....................................................................... 79
6.3　循環(huán)結(jié)構(gòu) ..........................................................................................................79
6.3.1　使用for 語句 ....................................................................................................79
實例6-7：計算某個整數(shù)的階乘 ............................................................................................... 80
6.3.2　使用while 循環(huán)語句 ........................................................................................81
實例6-8：依次輸出1*1、1*2…到1*20 的積 ........................................................................ 82
6.3.3　使用do-while 語句 ...........................................................................................83
實例6-9：猜數(shù)游戲 ................................................................................................................... 84
6.3.4　正確對待goto 語句 ..........................................................................................84
實例6-10：統(tǒng)計從鍵盤輸入一行字符的個數(shù) ......................................................................... 85
6.3.5　使用break 語句 ................................................................................................85
實例6-11：計算圓的面積 ......................................................................................................... 86
6.3.6　使用continue 語句 ...........................................................................................86
實例6-12：輸出顯示100 到200 之間的不能被3 整除的整數(shù) ............................................. 87
6.3.7　死循環(huán)/ 退出程序 ............................................................................................87
第7 章　數(shù)組存儲數(shù)據(jù)
7.1　使用一維數(shù)組 ..................................................................................................89
7.1.1　定義一維數(shù)組 ...................................................................................................89
7.1.2　引用即使用 .......................................................................................................90
實例7-1：輸出數(shù)組內(nèi)的各個元素值 ....................................................................................... 91
7.1.3　數(shù)組需要初始化 ...............................................................................................91
實例7-2：實現(xiàn)一個由小到大排列的冒泡程序 ....................................................................... 92
7.2　多維數(shù)組 ..........................................................................................................93
7.2.1　二維數(shù)組 ...........................................................................................................93
實例7-3：輸出顯示10 行楊輝三角 ......................................................................................... 95
7.2.2　使用多維數(shù)組 ...................................................................................................96
實例7-4：獲取成績分的球員編號 ................................................................................... 98
7.3　使用字符數(shù)組與字符串 ..................................................................................99
7.3.1　侃侃字符數(shù)組 ...................................................................................................99
7.3.2　字符串與字符數(shù)組 .........................................................................................100
7.3.3　字符數(shù)組的輸入輸出 .....................................................................................101
實例7-5：比較兩個字符串的大小 ......................................................................................... 102
7.4　使用字符處理函數(shù)和字符串處理函數(shù) ........................................................103
7.4.1　使用測試字符串長度函數(shù)strlen ...................................................................103
實例7-6：使用函數(shù)strlen 輸出程序中數(shù)組字符串的長度 .................................................. 103
7.4.2　使用字符串大小寫轉(zhuǎn)換函數(shù)strupr 和strlwr ...............................................103
實例7-7：分別輸出輸入字符串的小寫形式和大寫形式 ..................................................... 103
7.4.3　使用字符串復制函數(shù)strcpy 和strncpy ........................................................104
實例7-8：復制用戶輸入的字符串 ......................................................................................... 104
7.4.4　使用字符串比較函數(shù)strcmp 和strncmp ......................................................105
實例7-9：比較用戶輸入的字符串 ......................................................................................... 106
7.4.5　使用字符串連接函數(shù)strcat 和strncat ...........................................................106
實例7-10：連接用戶輸入的字符串 ....................................................................................... 107
7.4.6　將字符串轉(zhuǎn)換成數(shù)值的函數(shù) .........................................................................108
實例7-11：將用戶輸入的字符串轉(zhuǎn)換為數(shù)值類型的值 ....................................................... 108
7.4.7　使用字符檢測函數(shù) .........................................................................................109
實例7-12：判斷字符串中各字符所占用的個數(shù) ................................................................... 109
7.4.8　使用字符大小寫轉(zhuǎn)換函數(shù)tolower 和toupper ..............................................110
實例7-13：將字符串分別輸出轉(zhuǎn)換為大寫形式和小寫形式 ................................................111
第8 章　函數(shù)
8.1　函數(shù)基礎(chǔ)知識介紹 ........................................................................................ 112
8.1.1　函數(shù)的分類 .....................................................................................................112
8.1.2　函數(shù)的定義 .....................................................................................................114
實例8-1：比較兩個數(shù)字的大小 ..............................................................................................114
8.2　函數(shù)聲明和函數(shù)原型 .................................................................................... 115
8.2.1　函數(shù)聲明 .........................................................................................................115
實例8-2：求s=(1 2 3 … n)/(1 2 3 … m) 的值 ...............................................................116
8.2.2　函數(shù)原型 .........................................................................................................117
8.3　函數(shù)的參數(shù) .................................................................................................... 117
8.3.1　形參和實參詳解 .............................................................................................117
實例8-3：計算從1 到某個數(shù)字值的和 ..................................................................................118
8.3.2　將數(shù)組作為函數(shù)參數(shù) .....................................................................................118
實例8-4：判斷一個整數(shù)是否大于0 .......................................................................................119
實例8-5：互換二維數(shù)組中行和列的元素 ............................................................................. 120
8.4　函數(shù)的返回值 ................................................................................................120
實例8-6：計算兩個整數(shù)3 和4 的和 ..................................................................................... 121
8.5　實現(xiàn)函數(shù)的調(diào)用 ............................................................................................122
8.5.1　調(diào)用函數(shù)的格式 .............................................................................................122
實例8-7：比較3 個數(shù)字的大小 ............................................................................................. 122
8.5.2　函數(shù)調(diào)用的方式 .............................................................................................123
實例8-8：計算公約數(shù)和小公倍數(shù) ............................................................................. 123
8.6　函數(shù)的嵌套調(diào)用和遞歸調(diào)用 ........................................................................124
8.6.1　函數(shù)嵌套調(diào)用詳解 .........................................................................................124
實例8-9：輸出字符串中長的單詞 ..................................................................................... 125
8.6.2　函數(shù)遞歸調(diào)用 .................................................................................................126
實例8-10：實現(xiàn)數(shù)學中Hanoi 塔問題的解決方案................................................................ 127
8.7　變量的作用域 ................................................................................................129
8.7.1　局部變量作用域 .............................................................................................129
實例8-11：計算長方體的體積和三個面的面積 ................................................................... 129
8.7.2　全局變量作用域 .............................................................................................130
實例8-12：超市價格調(diào)整 ....................................................................................................... 130
8.8　靜態(tài)存儲變量和動態(tài)存儲變量 ....................................................................131
8.8.1　靜態(tài)存儲和動態(tài)存儲的區(qū)別 .........................................................................132
8.8.2　四種變量存儲類型 .........................................................................................132
8.8.3　自動變量 .........................................................................................................132
8.8.4　外部變量 .........................................................................................................133
實例8-13：在函數(shù)間通過外部函數(shù)直接傳遞數(shù)據(jù) ............................................................... 134
8.8.5　靜態(tài)變量 .........................................................................................................134
實例8-14：使用靜態(tài)變量設置初始值 ................................................................................... 136
8.8.6　寄存器變量 .....................................................................................................136
實例8-15：使用register 變量提升效率 ................................................................................. 136
8.9　內(nèi)部函數(shù)和外部函數(shù) ....................................................................................137
8.9.1　內(nèi)部函數(shù)詳解 .................................................................................................137
實例8-16：在不同的文件內(nèi)使用同一個名稱的函數(shù) ........................................................... 138
8.9.2　使用外部函數(shù) .................................................................................................138
實例8-17：在一個文件內(nèi)調(diào)用另一個外部函數(shù) ................................................................... 138
8.10　庫函數(shù) ..........................................................................................................139
8.10.1　庫函數(shù)介紹 ...................................................................................................139
8.10.2　庫函數(shù)的分類 ...............................................................................................139
第9 章　使用指針
9.1　指針和內(nèi)存地址 ............................................................................................141
9.2　變量的指針和指向變量的指針變量 ............................................................142
9.2.1　聲明指針變量 .................................................................................................142
9.2.2　初始化指針變量 .............................................................................................143
9.2.3　引用指針變量 .................................................................................................144
實例9-1：將兩個指針變量分別指向兩個變量 ..................................................................... 145
9.2.4　指針運算符 .....................................................................................................145
實例9-2：對輸入的數(shù)字進行排序處理 ................................................................................. 146
9.2.5　指針變量的運算 .............................................................................................147
實例9-3：順序顯示數(shù)組內(nèi)的元素并分別逆向輸出 ............................................................. 148
9.2.6　指針變量作為函數(shù)參數(shù) .................................................................................148
實例9-4：按照從小到大的順序排序輸出三個整數(shù) ............................................................. 150
9.2.7　void 類型的指針 .............................................................................................151
實例9-5：定義4 個類型的變量，然后分別輸出轉(zhuǎn)換后的結(jié)果 ......................................... 151
9.3　指針和數(shù)組 ....................................................................................................152
9.3.1　數(shù)組元素的指針 .............................................................................................153
9.3.2　指向一維數(shù)組元素的指針變量 .....................................................................154
9.3.3　通過指針引用數(shù)組元素 .................................................................................155
實例9-6：分別通過指向數(shù)組的指針引用數(shù)組、利用數(shù)組名和下標引用數(shù)組 ................. 156
9.3.4　數(shù)組名作函數(shù)參數(shù) .........................................................................................158
實例9-7：將數(shù)組中的元素按相反順序存放 ......................................................................... 158
實例9-8：輸出數(shù)組元素中的值和小值 ..................................................................... 159
9.4　指針和多維數(shù)組 ............................................................................................160
9.4.1　多維數(shù)組的地址 .............................................................................................160
實例9-9：輸出顯示二維數(shù)組元素的地址 ............................................................................. 162
9.4.2　指向多維數(shù)組的指針變量 .............................................................................162
實例9-10：2*3 或3*4 矩陣相乘運算 .................................................................................... 164
9.5　指針和字符串 ................................................................................................165
9.5.1　指針訪問字符串 .............................................................................................165
實例9-11：把一個字符串的內(nèi)容復制到另一個字符串中 ................................................... 166
9.5.2　字符串指針作函數(shù)參數(shù) .................................................................................167
實例9-12：使用函數(shù)調(diào)用復制字符串的內(nèi)容 ....................................................................... 167
9.6　指針數(shù)組和多級指針 ....................................................................................168
9.6.1　指針數(shù)組 .........................................................................................................168
9.6.2　多級指針的定義和應用 .................................................................................169
實例9-13：對5 個字符串進行排序 ....................................................................................... 170
9.6.3　指向指針的指針 .............................................................................................171
9.6.4　main 函數(shù)的參數(shù) ............................................................................................171
實例9-14：使用帶參數(shù)的main 函數(shù)輸出指針數(shù)組參數(shù)的值 ............................................. 172
9.7　指針函數(shù)和函數(shù)指針 ....................................................................................173
9.7.1　指針函數(shù) .........................................................................................................173
9.7.2　函數(shù)指針 .........................................................................................................173