how to replace string in php code example

Example 1: php str_replace

<?php
//str_replace("Original Value", "Value to be replaced", "String");
$result = str_replace("1", "2", "This is number 1");
// Output: This is number 2
?>

Example 2: str_replace php variable

$var1 = 'hello.world';
$var2 = str_replace(".", "-", $var1);
echo $var2; // hello-world

Example 3: php replace

str_replace ($search, $replace, $subject);

Example 4: str_replace php variable

$var1 = 'hello_john';
$var2 = str_replace("_", "-", $var1);
echo $var2; // hello-john

Example 5: str_replace php

str_replace ( array|string $needle , array|string $needle_replacement , string|array $haystack , int &$output_count = null ) : string|array
str_replace ($needle, $needle_replacement, $haystack, $output_count);
  // $needle --> the string value or array of string values you're looking for
  // $needle_replacement --> the string value or array of string values you'll replace the needle(s) with
  // $haysytack --> the string or array of strings you'd like to search/replace needles in
  // $output_count --> not an input, but can be used to get an aggregator to count how many needles were replaced

str_replace ($needle, $needle_replacement, $haystack) //w/out count