c2059在循环C做错误，出了什么问题？

Question

我的代码：

#include "cs50.h"
#include <stdio.h>
#include <math.h>

int main (void)
{
    do
    {
        printf("How much money do I owe you ?\n");
        float change = GetFloat(); //gets a floating point value from the user
        if(change <0.01 )
        {
            printf("Try again you big dummy\n");
        }
        else
        {
            printf("Capitalism Ho!\n");
        }
    }
    while (float change < 0.00); //this is line 20
}

在编译器中：

greedo.c（20）错误2059：语法错误：“类型”

这是cs50问题集1的一部分

Answer 1

1）您需要消除while（）表达式中的“浮动更改”

2）您应该将“浮动更改”的声明移到顶部

#include "cs50.h"
#include <stdio.h>
#include <math.h>

int main (void)
{
    float change;
    do
    {
        printf("How much money do I owe you ?\n");
        change = GetFloat(); //gets a floating point value from the user
        if(change <0.01 )
        {
            printf("Try again you big dummy\n");
        }
        else
        {
            printf("Capitalism Ho!\n");
        }
    }
    while (change < 0.00); //this is line 20
}

3）我还建议定义一个“最小值”，然后检查它：

#include "cs50.h"
#include <stdio.h>
#include <math.h>

#define MIN_VALUE 0.01

int main (void)
{
    float change;
    do
    {
        printf("How much money do I owe you ?\n");
        change = GetFloat(); //gets a floating point value from the user
        if(change >= MIN_VALUE)
        {
            printf("Capitalism Ho!\n");
            break;
        }
    }
    while (change < MIN_VALUE); //this is line 20
}

Answer 2

该行语法无效。将其更改为：

while (change < 0.00); //this is line 20