把字符转换成数字: char a='6'; int j=0; j=(int )(a-'0'); 把数字转化成字符: int a='6'; char j=NULL; j=a+'0';
把字符串转换成数组
#include <iostream>
#include<string.h>
#include<stdio.h>
int main()
{
int num=0;
char *s="123456";
printf("=%d\n",sizeof(s));
while(*s)
{
num=num*10+*s-'0';//在这里把123456转化成数字123456的原理就是*s=1时,num=0*10+1-0=1,s=2时,s=1*10+2-0=12;*s=3时,num=12*10+3-0,*s=4时,num=123*10+4-0=1234,*s=5时,num=1234*10+5=12345,*s=6时,num=12345*10+6=123456。//
s++;
}
//printf("%d\n",strlen(num));
printf("%d\n",num);
return 0;
} liuzj@ET302Buildver:~/zhanghong$ g++ zifuchuan.cpp
zifuchuan.cpp: In function ‘int main()’:
zifuchuan.cpp:7:9: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
char *s="123456";
^
liuzj@ET302Buildver:~/zhanghong$ ./a.out
123456
liuzj@ET302Buildver:~/zhanghong$