c - 如何使用c合并两个字符串？

Question

#include<stdio.h>

/* a function to merge two strings */

void stringMerge(char* f, char* s){

while(*f++);

while((*f++ = *s++));

}

int main(){

char s1[] = "Hello ";

char s2[] = "World";

stringMerge(s1,s2);

printf("%s",s1);

return 0;

}

Answer 1

考虑到您要连接的字符串的声明，那么您似乎意味着以下函数实现。

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

char * stringMerge(const char *s1, const char *s2)
{
    size_t n = strlen(s1);

    char *p = (char *)malloc(n + strlen(s2) + 1);

    if (p)
    {
        strcpy(p, s1);
        strcpy(p + n, s2);
    }

    return p;
}


int main( void )
{
    char s1[] = "Hello ";
    char s2[] = "World";

    char *p = stringMerge(s1, s2);

    puts(p);

    free(p);
}

或以下内容

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

char * stringMerge(const char *s1, const char *s2)
{
    size_t n = strlen(s1);

    char *p = (char *)malloc(n + strlen(s2) + 1);

    if (p)
    {
        char *t = p;
        while (*t = *s1++) ++t;
        do { *t = *s2++; } while (*t++);
    }

    return p;
}

int main( void )
{
    char s1[] = "Hello ";
    char s2[] = "World";

    char *p = stringMerge(s1, s2);

    puts(p);

    free(p);
}

在这两个程序中，输出是

Hello World