Using str_replace() in PHP: Syntax, Parameters, and Examples

In PHP, string manipulation is common, and the str_replace() function is widely used to replace specific characters or substrings within a string.

The syntax of str_replace() is:

str_replace(search, replace, subject)

Parameter description:

search : the value to be replaced; can be a string or an array of strings.

replace : the replacement value; can be a string or an array that must correspond to search when both are arrays.

subject : the target string or array of strings on which the replacement is performed.

Return value:

The function returns the string after all replacements have been applied.

Example 1: Replacing a single substring

$str = "Hello, World!";
$newStr = str_replace("World", "PHP", $str);
echo $newStr; // Output: Hello, PHP!

This example replaces "World" with "PHP" and prints the result.

Example 2: Replacing multiple substrings

$str = "Hello, World!";
$search = array("Hello", "World");
$replace = array("Hi", "PHP");
$newStr = str_replace($search, $replace, $str);
echo $newStr; // Output: Hi, PHP!

Here both "Hello" and "World" are replaced simultaneously.

Example 3: Case‑insensitive replacement

$str = "Hello, world!";
$newStr = str_ireplace("WORLD", "PHP", $str);
echo $newStr; // Output: Hello, PHP!

The str_ireplace() function performs a case‑insensitive replacement.

Summary

The str_replace() function is a flexible tool for PHP developers, capable of handling single or multiple replacements and offering case‑insensitive options via str_ireplace() . Mastering its parameters and usage can greatly simplify string manipulation tasks.

Additional learning resources:

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