PHP str_replace() Function

Syntax of str_replace in PHP

Here is the syntax of str_replace in PHP:

• $search (required): This parameter specifies the substring to be searched for within the $subject string. It can be a single string or an array of strings to search for.
• $replace (required): This parameter defines the string(s) that will replace the occurrences of the $search substring in the $subject string. It can be a single string or an array of strings. The replacement occurs in the same order as the search strings provided.
• $subject (required): The original string where replacements will be made.
• &$count (optional): This is a reference parameter that stores the number of replacements that were performed. If specified, it will be updated with the count of replacements made. This parameter is optional.

Parameters of str_replace in PHP

1. $search (required):

• Type: String or Array of strings
• Description: Specifies the substring(s) to be searched for within the $subject string. It can be a single string or an array of strings. If an array is provided, each element is treated as a separate search string.
• Example: "world", ["apple", "banana"]

2. $replace (required):

• Type: String or Array of strings
• Description: Defines the replacement string(s) that will replace the occurrences of the $search substring(s) in the $subject string. It can be a single string or an array of strings. The replacements occur in the same order as the search strings provided.
• Example: "universe", ["fruit", "fruit"]

3. $subject (required):

• Type: String
• Description: The original string where replacements will be made.
• Example: "Hello, world! Hello, PHP!"

4. &$count (optional):

• Type: Integer (reference)
• Description: This optional parameter is a reference variable that will hold the count of replacements made.
• Example: $count = 0;

Return Value of str_replace in PHP

The str_replace function in PHP returns a modified string or an array of strings after performing the specified replacements. The return value depends on the data type of the $search and $replace parameters:

1. If both $search and $replace are strings:

• The function returns a new string where all occurrences of the $search substring in the $subject string have been replaced with the $replace string.

2. If both $search and $replace are arrays of strings:

• The function returns an array of strings where each element of the array corresponds to the $subject string with replacements applied according to the order of elements in the $search and $replace arrays.

3. If $search is an array and $replace is a string:

• The function performs replacements on each element of the $search array using the same $replace string, and it returns an array of strings with the replacements.

Examples

Using str_replace() with an array and a count variable

Output

• The $originalString contains the text where replacements need to be performed.
• The $search array contains the substrings "sun," "sky," and "birds" that we want to search for in the original string.
• The $replace string is set to "nature," which will be used to replace occurrences of the substrings in the $search array.
• The $count variable is initialized to 0. It will be used to store the number of replacements made during the operation.
• The str_replace() function is called with the $search, `$replace, and $originalString parameters, along with the reference to the $count` variable. The function returns the modified string with replacements.
• The modified string is then echoed to the output, and the count of replacements stored in the $count variable is displayed. Run the above code in your editor for a better and clearer explanation.

sing str_replace() with fewer elements in replace than find

Output

• The $originalString contains the text where replacements need to be performed.
• The $search array contains the substrings "apples," "red," and "green" that we want to search for in the original string.
• The $replace array contains a single element "oranges," which will be used as a replacement for occurrences of the find elements.
• The str_replace() function is called with the $search, ``$replace, and $originalString parameters. Since there are fewer elements in the $replace array than in the $search array, the "oranges" replacement will be applied to each corresponding occurrence of the find elements.
• The modified string is then echoed to the output. Run the above code in your editor for a better and clearer explanation.

Replacing all the search strings with replacing strings using the str_replace() function

Output

• The $originalText variable contains the text where replacements need to be performed.
• The $search array contains the substrings "quick," "fox," "lazy," and "dog" that we want to search for in the original text.
• The $replace array contains the corresponding replacement strings "fast," "cat," "active," and "puppy."
• The str_replace() function is called with the $search, $replace, and $originalText parameters. It scans through the original text and replaces each occurrence of a search string with its corresponding replacement string from the arrays.
• The modified text is then echoed to the output. Run the above code in your editor for a better and clear explanation.