Question

我试图编写一个程序来删除用户输入的最后一个换行符，即用户在键入字符串后按Enter键时生成的换行符。

void func4()
{

    char *string = malloc(sizeof(*string)*256); //Declare size of the string
    printf("please enter a long string: ");
    fgets(string, 256, stdin);  //Get user input for string (Sahand)
    printf("You entered: %s", string); //Prints the string

    for(int i=0; i<256; i++) //In this loop I attempt to remove the newline generated when clicking enter
                            //when inputting the string earlier.
    {
        if((string[i] = '\n')) //If the current element is a newline character.
        {
            printf("Entered if statement. string[i] = %c and i = %d\n",string[i], i);
            string[i] = 0;
            break;
        }
    }
    printf("%c",string[0]); //Printing to see what we have as the first position. This generates no output...

    for(int i=0;i<sizeof(string);i++) //Printing the whole string. This generates the whole string except the first char...
    {
        printf("%c",string[i]);
    }

    printf("The string without newline character: %s", string); //And this generates nothing!

}

但它并没有像我想象的那样表现。这是输出：

please enter a long string: Sahand
You entered: Sahand
Entered if statement. string[i] = 
 and i = 0
ahand
The string without newline character: 
Program ended with exit code: 0

问题：

为什么该程序似乎与'\n'匹配第一个字符'S'？
为什么当我还没有从字符串中删除任何内容时，最后一行printf("The string without newline character: %s", string);根本没有产生输出？
如何让这个程序按照我打算做的去做？

Answer 1

条件(string[i] = '\n')将始终返回true。它应该是(string[i] == '\n')。

Answer 2

if((string[i] = '\n'))

这一行可能有误，你将值赋给string [i]，而不是比较它。

if((string[i] == '\n'))

C：尝试从字符串

2 个答案: