(1)输入输出
输入运算符“>>”默认会忽略空格,遇到空格就认为输入结束;
>> cin string
<< cin
(2) 获取长度
strlen(str)来获取char数组的实际长度 #include <cstring>
char str[20]="0123456789";
int a = strlen(str); //a=10; strlen 计算字符串的长度,以\0'为字符串结束标记。
cout << a;
获取string 实际长度
s.length()
string s = "hello world";
int len = s.length();
(3) 访问字符
String可以像字符串数组一样按照下标来访问其中的每一个字符;
for (int i = 0; i < s1.length(); i++){
cout <<s1[i] << endl;
}
cout << "迭代方式:" << endl;
for (string::iterator it = s1.begin(); it != s1.end(); it++){
cout<<*it<< endl;
}
(4)拼接字符串
+“ 或者”+=“运算符来直接拼接字符串
string s = s1 + s2;
s.append(s3);
(5 ) 相互转换
使用文件打开函数,必须将string类型的变量转换为字符串数组
//string -> char*
string s1 = "far away";
const char* c = s1.c_str(); // const
printf("%s\n",c);
string s1 = "far away";
const char* c = s1.c_str(); // const
printf("%s\n",c);
//
string s2 = c;
string s2 = c;
//string->char[]
//从string中赋值字符到char[]
char arr[50] = {0};
s1.copy(arr,5,0);
//从string中赋值字符到char[]
char arr[50] = {0};
s1.copy(arr,5,0);
cout << arr << endl;