C语言strtod函数DEMO

参考文献

#include
#include
void main()
{
    char *endptr;
    char* ptr;
    char a[] = "a12345.6789";
    char b[] = "1234.567qwer";
    char c[] = "-232.23e4";
    printf( "a=%lf\n", strtod(a, &ptr) );
    if (a==ptr)
    {
        printf("a and ptr is equality\n");
        /* 只有当带转换字符串第一个字符是非数字字符时候，a ptr 两个指针才相等; */
    }else{
         printf("a and ptr is not equality\n");
    }
    printf( "b=%lf\n", strtod(b,&endptr) );
    //因为b字符串后面有非数字字符 ，endptr指针指向q字符，也只是转换到p，
    if (b==endptr)
    {
        printf("b and endptr is equality\n");
        /* code */
    }else{
         printf("b and endptr is not equality\n");
    }
    printf( "endptr=%s\n", endptr );
    printf( "c=%lf\n", strtod(c,NULL) );
    /* fprintf(stderr, "%s:%d: expect: " format " actual: " format "\n", __FILE__, __LINE__, expect, actual);\*/
    fprintf(stdout, "fprintf first:  %s\t""second:  %s\n", a,b);/*  C fprintf函数format字符串可以用两个双引号构成*/
    /*printf(stdout, "printf first%s\t""printf second %s\n",c,a );   no way  buxing*/
}

输出：