/1)字符串复制函数 strcpy()//strcpy 是 string copy 的缩写
strcpy(a,b)相当于a=b,将字符串b赋给a
需要头文件string.h的支持/
/*
#include <stdio.h>#include <string.h>int main() {char a[50] ="abc";char b[50] = "cde";strcpy(a, b);printf("a: %s\n", a);return 0;//cde}
*/
/*2)获取字符串长度strlen(a)//string length
计算字符串的实际长度（不含字符串结束标志“\0”）, 函数返回值为字符串的实际长度
/
/
#include<stdio.h>#include<string.h>int main() {char a[] = {"abc" };printf("%d\n%d", strlen(a), sizeof(a));//3 4return 0;}
/
//3)字符串连接函数 strcat(a,b)//string catenate
//a=a+b
/
#include <stdio.h>#include <string.h>int main(){char a[] = "abc";char b[] = "cde";strcat(a, b);puts(a);//abcdereturn 0;}
/
/
4)字符串比较函数 strcmp(a, b)// string compare
按照ASCII码顺序比较两个字符数组中的字符, 逐个比较
a = b，返回0
a > b，返回正数
a < b，返回负数
if (strcmpa(a, b) == 0) == a == b
if (strcmpa(a, b) > 0) == a > b
if (strcmpa(a, b) < 0) == a < b
if (strcmpa(a, b) != 0) == a != b
/
/
#include<stdio.h>#include<string.h>void main(){char a[] = "abc", b[] = "abc";if (strcmp(a, b)){printf("aaaa");}else{printf("bbbb");}}//bbbb
*/
/*5)字符串大小写转换
strupr(a)
将字符串中的小写字母转换成大写字母
strlwr(a)
将字符串中的大写字母转换成小写字母
*/
#include<stdio.h>#include<string.h>void main(){char a[] = "aBcD", b[] = "aBcD";printf("%s\n%s", strlwr(a), strupr(b));}//abcd ABCD
