如何将字符串转换为浮点数?

#include<stdio.h>
#include<string.h>

int main() 
{
    char s[100] ="4.0800" ; 

    printf("float value : %4.8f\n" ,(float) atoll(s)); 
    return 0; 
}
#include<stdio.h>
#include<string.h>

int main(