参考文献

#include<stdlib.h>
#include<stdio.h>
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*/
}

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