The print_r() function is a built-in function in PHP and is used to print or display information stored in a variable.
Syntax:
print_r( $variable, $isStore )
Parameters: This function accepts two parameters as shown in above syntax and described below.
- $variable: This parameter specifies the variable to be printed and is a mandatory parameter.
- $isStore: This an option parameter. This parameter is of boolean type whose default value is FALSE and is used to store the output of the print_r() function in a variable rather than printing it. If this parameter is set to TRUE then the print_r() function will return the output which it is supposed to print.
Return Value: If the $variable is an integer or a float or a string the function prints the value of the variable. If the variable is an array the function prints the array in a format which displays the keys as well as values, a similar notation is used for objects. If the parameter $isStore is set to TRUE then the print_r() function will return a string containing the information which it is supposed to print.
Below programs illustrate the print_r() function:
Program 1:
<?php   // PHP program to illustrate // the print_r() function   // string variable $var1 = "Welcome to neveropen";   // integer variable $var2 = 101;   // array variable $arr = array('0' => "Welcome", '1' => "to", '2' => "neveropen");   // printing the variables print_r($var1); echo"\n"; print_r($var2); echo"\n"; print_r($arr);   ?> |
Output:
Welcome to neveropen
101
Array
(
[0] => Welcome
[1] => to
[2] => neveropen
)
Program 2:
<?php   // PHP program to illustrate the print_r() // function when $isStore is set to true   // array variable $arr = array('0' => "Welcome", '1' => "to",                      '2' => "neveropen");                        // storing output of print_r() function // in another variable $results = print_r($arr, true);   echo $results;   ?> |
Output:
Array
(
[0] => Welcome
[1] => to
[2] => neveropen
)
