如何用不同的字符替换字符串中的第一个空格？

Andrew Fox 发表于 Dev

安德鲁·福克斯

我有一个文本（.txt）文件，其中包含如下文本：

5 General
-10 Time Limits
-20 Scheduled Maintenance Checks
-30 Reserved 
-40 Reserved
-50 Unscheduled Maintenance checks

6 DIMENSIONS and AREAS

7 LIFTING and SHORING
-00 General
-10 Jacking
-20 Shoring

8 LEVELING and WEIGHING
-00 General
-10 Weighing and Balancing
-20 Leveling

9 TOWING and TAXIING
-00 General
-10 Towing
-20 Taxiing

我想用逗号替换每行中的第一个空格（我正在尝试将txt文件转换为csv，以准备将其导入到db中）。我开始使用strpos()函数，但是无法理解下一步该做什么。

奖励任务：我还希望在每行的末尾添加半冒号。

编辑：添加了实际数据，而不是示例数据。

一个简单的带有限制的preg_replace将起作用：

$str = '5 Here is some text.';

echo preg_replace('/ /', ',', $str, 1); 

//  OUTPUT:
//  5,Here is some text.

带循环：

<?php

$str = array('5 Here is some text.', '5 Here is some text.','-10 Here is some text.','-20 Here is some text.','-30 Here is some text');
foreach ($str as $a) {
echo preg_replace('/ /', ',', $a, 1)."<br>";
}

// OUTPUT:
// 5,Here is some text.
// -10,Here is some text.
// -20,Here is some text.
// -30,Here is some text.

编辑您的新编辑：

$str = "5 General
-10 Time Limits
-20 Scheduled Maintenance Checks
-30 Reserved 
-40 Reserved
-50 Unscheduled Maintenance checks

6 DIMENSIONS and AREAS

7 LIFTING and SHORING
-00 General
-10 Jacking
-20 Shoring

8 LEVELING and WEIGHING
-00 General
-10 Weighing and Balancing
-20 Leveling

9 TOWING and TAXIING
-00 General
-10 Towing
-20 Taxiing";

$array = explode(PHP_EOL, $str);

foreach ($array as $a) {

echo preg_replace('/ /', ',', $a, 1)."<br>";
}

// OUTPUT:

/*
5,General
-10,Time Limits
-20,Scheduled Maintenance Checks
-30,Reserved
-40,Reserved
-50,Unscheduled Maintenance checks

6,DIMENSIONS and AREAS

7,LIFTING and SHORING
-00,General
-10,Jacking
-20,Shoring

8,LEVELING and WEIGHING
-00,General
-10,Weighing and Balancing
-20,Leveling

9,TOWING and TAXIING
-00,General
-10,Towing
-20,Taxiing
*/