while 循环不会以逻辑条件终止 [英] while loop won't terminate with a logical conditional

问题描述

如果我添加 OR 条件语句，此循环将不会终止.如果一个是假的，那么它应该终止.

This loop won't terminate if I add an OR conditional statement. If one is false, then it should terminate.

//全局变量

int x = 100;
    char *n= malloc (64);

void add(void)
{       

    do      
    {
        printf("Would you like to add 1? (y/n) ");
        fgets(n, 64, stdin);
            //removes newline
        n[strlen(n)-1] = '';
            x++;
    }       
//if I add || (x!=100) it keeps looping me even if I press "n"
//otherwise without it it works fine

        while((strncmp(n, "n", 1) != 0) || x!=100 );

        free(n);
}

推荐答案

在循环的底部，您正在执行 x++.一旦你遇到 while 条件，x == 101，所以你的循环永远不会终止，x 在条件被检查时永远不会等于 100.

At the bottom of your loop, you're doing x++. Once you hit the while condition, x == 101, so your loop never terminates, x never equals 100 when the condition is being checked.

也许你想要:

while((strncmp(n, "n", 1) != 0) && x != 100);

如果两个条件中的任何一个为假，哪个将终止循环.

Which would terminated the loop if either of the two conditions is false.

&& 是逻辑与"运算符，|| 是逻辑或"运算符.为了帮助您进行跟踪，您可以使用真值表来帮助您理清细节.逻辑和与逻辑合取和逻辑或与逻辑析取相同.

&& is the 'logical and' operator, || is the 'logical or' operator. To help you keep track, you can use a Truth Table to help you sort out the details. Logical and is the same as logical conjunction and logical or is the same as logical disjunction.

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