编写一个方法来替换C样式字符串中的所有空格

#include<stdio.h>
#include<string.h>

void replaceSpaces(char* str, char replaceChar) {
    int length = strlen(str);
    int i;

    for (i = 0; i< length; i++) {
        if (str[i] == ' ') {
            str[i] = replaceChar;
        }
    }
}

int main() {
    char str[] = "This is a C style string.";
    replaceSpaces(str, '_');
    printf("%s\n", str);
    return 0;
}