在字符串中的每个字符之间添加“ - ”？

How to do that? I am willing to add the character - after every character in a certain string. For a specific case assume I have a string declared in the size of 100 but filled with only 3 letters (entered by the user - so the value of the character str[3] is NULL (\0)).

怎么做?我愿意添加字符 - 在某个字符串中的每个字符之后。对于特定情况,假设我有一个声明为100的字符串,但只填充了3个字母(由用户输入 - 因此字符str [3]的值为NULL(\ 0))。

for(i = strlen(str) ; i >= 0 ; i--)
{
    str[i*2] = str[i];
}
for(i = 0 ; i < strlen(str) ; i++)
{
    if(i % 2 != 0)
    {
        str[i] = '-';
    }
}

but it's not working, help anyone?

但它不起作用,帮助任何人?

4 个解决方案

#1

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

int main()
{
   char str[100];
   int len = 0;
   int i = 0;
   strcpy(str, "abcd");

   len = strlen(str);
   // len = 4

   // Expected output: "a-b-c-d"
   // str[7] = '\0';
   // str[6] = 'd';
   for(i = len-1; i >= 0 ; i--)
   {
      str[i*2+1] = '-';
      str[i*2] = str[i];
   }
   str[len*2-1] = '\0';

   printf("%s\n", str);
}

#2

You forgot to handle the terminating zero of the string in the first loop. After it, the original terminating zero is still in place:

你忘了在第一个循环中处理字符串的终止零点。之后,原始终止零仍然存在:

A S D \0
A S S \0 D x \0

So at the beginning of the second loop strlen(str) is still 3.

所以在第二个循环开始时,strlen(str)仍然是3。

When the second loop gets to the first \0 to replace it with -, the loop terminates instead, due to the condition in the for statement.

当第二个循环到达第一个\ 0以用 - 替换它时,由于for语句中的条件,循环终止了。

You'd better insert the hyphens straight away in the first loop.

你最好在第一个循环中直接插入连字符。

for (i = strlen(str); i > 0; i--) {
    str[i*2] = str[i];
    str[i*2-1] = '-';
}

Note, the loop above goes down to 1 only, as you can leave the A in place anyway.

请注意,上面的循环只会降为1,因为无论如何都可以将A留在原位。

#3

You can use a secondary string to store your changed results.

您可以使用辅助字符串来存储更改的结果。

char str[100] = "ASD";
char changed[100*2 - 1] = "";
for(int i = 0, j = 0; i < strlen(str); i++, j+=2)
{
    changed[j] = str[i];
    if (i < strlen(str)-1)
    {
        changed[j + 1] = '-';
    }
}

for (int i = 0; i < strlen(changed); i++)
{
    printf("%c", changed[i]);
}

#4

use only first for loop and make this changes to your for loop

仅使用first for循环并对for循环进行此更改

for(i = strlen(str)-1 ; i > 0 ; i--)
{
   str[i*2] = str[i];
   str[i*2-1] = '-';
}

#1

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

int main()
{
   char str[100];
   int len = 0;
   int i = 0;
   strcpy(str, "abcd");

   len = strlen(str);
   // len = 4

   // Expected output: "a-b-c-d"
   // str[7] = '\0';
   // str[6] = 'd';
   for(i = len-1; i >= 0 ; i--)
   {
      str[i*2+1] = '-';
      str[i*2] = str[i];
   }
   str[len*2-1] = '\0';

   printf("%s\n", str);
}

#2