The is_numeric() function is an inbuilt function in PHP which is used to check whether a variable passed in function as a parameter is a number or a numeric string or not. The function returns a boolean value.
Syntax:
bool is_numeric ( $var )
Parameters: The function accepts a single parameter which is mandatory and described below:
- $var: This input parameter is the variable which the function checks for whether it is a number or a numeric string. Based on this verification, the function returns a boolean value.
Return Value: The function returns TRUE if $var is a number or a numeric string and returns FALSE otherwise.
Examples:
Input : $var = 12 Output : True Input : $var = "Geeks for Geeks" Output : False
Below programs illustrate the is_numeric() function:
Program 1: In this program, a number is passed as input.
PHP
<?php$num = 12;if (is_numeric($num)) { echo $num . " is numeric"; } else { echo $num . " is not numeric"; }?> |
Output:
12 is numeric
Program 2: In this program, a string is passed as input.
PHP
<?php$element = "Geeks for Geeks";if (is_numeric($element)) { echo $element . " is numeric"; } else { echo $element . " is not numeric"; }?> |
Output:
Geeks for Geeks is not numeric
Program 3: In this program, a numeric string is passed as input.
PHP
<?php$num = "467291";if (is_numeric($num)) { echo $num . " is numeric"; } else { echo $num . " is not numeric"; }?> |
Output:
467291 is numeric
Program 4:
PHP
<?php$array = array( "21/06/2018", 4743, 0x381, 01641, 0b1010010011, "Geek Classes");foreach ($array as $i) { if (is_numeric($i)) { echo $i . " is numeric"."\n"; } else { echo $i . " is NOT numeric"."\n"; }}?> |
Output:
21/06/2018 is NOT numeric 4743 is numeric 897 is numeric 929 is numeric 659 is numeric Geek Classes is NOT numeric
