Why Str_replace returned data errors

Example: Replace comma, space character, or Chinese comma
$str = ' correct, contact us goodsjob,goodsjob ';
$reg = Array (', ', ' ', ', ');
$strs = ' username '. Str_replace ($reg, '%, or username like% ', $str). ' %';
The returned data is: username like% correct%,%, or username like%or%, or username like%username%, or username like%like%, or username like Percent% contact us%, or username like%goodsjob%, or username like%goodsjob%, for what?

The correct result should be: Usernme like% correct%, or username like% contact us%, or username like%goodsjob%

Reply content:

Example: Replace comma, space character, or Chinese comma
$str = ' correct, contact us goodsjob,goodsjob ';
$reg = Array (', ', ' ', ', ');
$strs = ' username '. Str_replace ($reg, '%, or username like% ', $str). ' %';
The returned data is: username like% correct%,%, or username like%or%, or username like%username%, or username like%like%, or username like Percent% contact us%, or username like%goodsjob%, or username like%goodsjob%, for what?

The correct result should be: Usernme like% correct%, or username like% contact us%, or username like%goodsjob%

Replace the space with other characters $str in the process of substitution, = "%, or username like%, there is also a string that satisfies your substitution rules so it will affect the result

        $str = '正确,联系我们 goodsjob，goodsjob';        $str = str_replace(' ', ' ', $str);        $reg = array(',','，'," ");        $strs = 'username like %'.str_replace($reg,'%, or username like %',$str).'%';                

注意：Because the Str_replace () function replaces left-to-right, it may replace the previously inserted value with multiple substitutions.

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