Summary of methods for inserting substrings into PHP strings Original PHP splits strings PHP converts strings to numbers PHP intercepts the first few characters of a string

The example in this article describes the method of inserting substrings into PHP strings. Share it with everyone for your reference, the details are as follows:

First, let’s take a look at a common method on the Internet:

Method 1: String traversal

function str_insert($str, $i, $substr)
{
  for($j=0; $j<$i; $j++){
    $startstr .= $str[$j];
  }
  for ($j=$i; $j<strlen($str); $j++){
    $laststr .= $str[$j];
  }
  $str = ($startstr . $substr . $laststr);
  return $str;
}
$str="1234567890";
$sstr="new_word";
echo str_insert($str,5,$sstr);//输出：12345new_word67890

The above method uses string traversal and reorganization to achieve the insertion of substrings Function.

Let’s take a look at an improvement method given by this site:

Method 2: Use the substr function to intercept and combine

function str_insert2($str,$i,$substr){//方法二：substr函数进行截取
  $start=substr($str,0,$i);
  $end=substr($str,$i);
  $str = ($start . $substr . $end);
  return $str;
  //return substr($str,0,$i).$substr.substr($str,$i);//上述代码可综合成这一句
}
$str="1234567890";
$sstr="new_word";
echo str_insert2($str,5,$sstr);//输出：12345new_word67890

This method directly uses the substr function to intercept the string, and then assemble the string. This achieves the insertion effect of substrings.

Finally, this site provides you with the most direct method:

Method 3: Directly use the substr_replace function to insert substrings

echo substr_replace($str,$sstr,5,0);
//此处直接输出：12345new_word67890

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I hope this article will be helpful to everyone in PHP programming.

The above is a summary of the method of inserting substrings into PHP strings. It is original, including strings and PHP content. I hope it will be helpful to friends who are interested in PHP tutorials.