Strings in PHP are similar to the ones used in other languages. They define a group of characters combined together to form a string. There are several string functions which can be easily used for data manipulation. User does not to perform separate installation. There are various representation of strings. The single quoted strings are defined as literals. Double quoted string are defined as variables whose values can be easily replaced. Example: Code: <html> <body> <?php $var = "age"; $literal = ‘Welcome and learn PHP’; echo ($literal); echo "<br/>"; $literal = "Harry completed $var years"; echo ( $literal); ?> </body> </html> User can delimit the string using double quotes. User can execute the string in two different ways as: The character sequence starting with the backslash ( \ ) is modified with the special character The names of the variables are replaced with the string values The various escape sequence replacements used in PHP are as mentioned below: The \r character is replaced with the carriage return The \$ replaced the dollar sign The \n replaces the newline character The \t defines the tab character \\ is changed with the single backslash The \" is modified with the single double quote String functions Let’s explore some of the string functions used for manipulating the strings in PHP. For complete list of string functions in PHP refer PHP.net here 1. Length of the string The strlen() function in PHP is used for manipulating the strings in PHP. The string is passed as the parameter to the function. Example: Code: <html> <body> <?php echo strlen ("Welcome"); ?> </body> </html> 2. Reverse of the string The strrev() function reverses the string defined in PHP. Example: Code: <html> <body> <?php echo strrev ("Welcome"); ?> </body> </html> 3. Covert the string to lowercase The characters of the string are converted into lowercase. Example: Code: <html> <body> <?php echo strtolower ("Welcome"); ?> </body> </html> 4. Convert the string to uppercase The characters of the string are converted into uppercase. Example: Code: <html> <body> <?php echo strtoupper ("Welcome"); ?> </body> </html> 5. Return the part of the string The substr() function is used for returning the part of the string. The parameters passed to the function are 1) string: The part of the string is returned 2) start: The position from where the string is starting 3) length: The length of the string is returned Example: Code: <html> <body> <?php echo substr ("Welcome User", 9)."<br>"; echo substr ("Welcome", 3)."<br>"; echo substr ("Welcome", 6)."<br>"; ?> </body> </html> 6. The position of the element in the string The strrpos() function is used to define the position of the occurrence of an element inside the string. The function consists of three parameters as mentioned below: 1) string: The string to be searched is defined 2) find: The string to be found is specified 3) start: Defines where to start the search Example: Code: <html> <body> <?php echo strrpos ("understand PHP, Learn understand PHP", "PHP"); ?> </body> </html> 7. Compare the two strings The strcmp() function is used for comparing the two strings. Example: Code: <html> <body> <?php echo strcmp ("Welcome User!!", "Welcome User!"); ?> </body> </html> 8. using the trim() function It is used for removing the whitespaces and other characters from the sides of the string. Example: Code: <html> <body> <?php $str1 = "Welcome"; echo $str1. "<br>"; echo trim ($str, "Wee"); ?> </body> </html>
