C++Primer习题(第三章附答案) .pdfVIP

C++Primer习题（第三章附答案） 练习3.1 略 练习 3. 2 编写⼀段程序从标准输⼊中⼀次读⼊⼀整⾏，然后修改程序使其⼀次读⼊⼀个词。 #include iostream #includestring using namespace std ; 使⽤ ⼀次读⼊⼀整⾏，回车结束 // getline int main() { string line ; cout please enter your line ,even space endl; 循环读取， 结束 while (getline(cin, line)) // Ctrl+c cout line endl; return 0; } #include iostream #includestring using namespace std ; 使⽤ ⼀次读⼊⼀单词，空⽩结束 // cin int main() { string word ; cout please enter your word ,not space endl; 循环读取， 结束 while (cinword) // Ctrl+c cout word endl; return 0; } 练习3.3 请说明string类的输⼊运算符和getline函数是如何分别处理空⽩字符的 #includeiostream #includestring using namespace std ; int main() { string word, line ; cout please select the way to read the string endl; cout 1 means read string by word endl; cout 2 means read string by line endl; char ch ; cin ch ; if (ch == 1) { cout please enter string : welcome to c++ family endl; cin word ; cout system read the string is : word endl; } else if (ch == 2) { cout please enter string : welcome to c++ family endl; getline(cin, line); cout system read the string is : line endl; } else { cout input error,please try again endl; } return 0; } 练习3.4 编写⼀段程序读⼊两个字符窜，⽐较其是否相等并输出结果。结果不相等，输出较⼤的那个字符串。改写上述程序，⽐较输⼊的两 个字符串是否等长，如果不等长，输出长度较⼤的那个字符串。 #includeiostream #includestring using namespace std ; int main() { string word1, word2 ; cout please enter two strings endl; cin word1 word2 ; if (word1 == word2) { cout word1 endl; } else if (word1word2) { cout word1 endl; } else { cout word2 endl; } return 0; } #includeiostream #includestring using namespace std ; int main() { string word1, word2 ; cout please ent