Add information "String" (#26594)

guide/english/php/strings/index.md

@@ -2,11 +2,54 @@
 title: Strings
 ---
 ## Strings
+A string is a sequence of characters, like "Hello world!".
 
+## PHP String Functions
+In this chapter we will look at some commonly used functions to manipulate strings.
+
+## Get The Length of a String
+The PHP strlen() function returns the length of a string.
+The example below returns the length of the string "Hello world!":
+````
+<?php
+echo strlen("Hello world!"); // outputs 12
+?>
+````
 A string is series of characters.
 PHP only supports a 256-character set and hence does not offer native Unicode support.
 
-<!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
+## Count The Number of Words in a String
+The PHP str_word_count() function counts the number of words in a string:
+````
+<?php
+echo str_word_count("Hello world!"); // outputs 2
+?>
+````
+
+## Reverse a String
+The PHP strrev() function reverses a string:
+````
+<?php
+echo strrev("Hello world!"); // outputs !dlrow olleH
+?>
+````
+
+## Search For a Specific Text Within a String
+The PHP strpos() function searches for a specific text within a string.
+If a match is found, the function returns the character position of the first match. If no match is found, it will return FALSE.
+The example below searches for the text "world" in the string "Hello world!":
+````
+<?php
+echo strpos("Hello world!", "world"); // outputs 6
+?>
+````
+
+## Replace Text Within a String
+````
+<?php
+echo str_replace("world", "Dolly", "Hello world!"); // outputs Hello Dolly!
+?>
+````
 
 #### More Information:
-<!-- Please add any articles you think might be helpful to read before writing the article -->
+[PHP String tutorial](https://www.w3schools.com/php/php_string.asp)