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 $num = 12;
if ( is_numeric ( $num )) {
echo $num . " is numeric" ;
}
else {
echo $num . " is not numeric" ;
}
?> |
12 is numeric
Program 2: In this program, a string is passed as input.
<?php $element = "Geeks for Geeks" ;
if ( is_numeric ( $element )) {
echo $element . " is numeric" ;
}
else {
echo $element . " is not numeric" ;
}
?> |
Geeks for Geeks is not numeric
Program 3: In this program, a numeric string is passed as input.
<?php $num = "467291" ;
if ( is_numeric ( $num )) {
echo $num . " is numeric" ;
}
else {
echo $num . " is not numeric" ;
}
?> |
467291 is numeric
Program 4:
<?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" ;
}
} ?> |
21/06/2018 is NOT numeric 4743 is numeric 897 is numeric 929 is numeric 659 is numeric Geek Classes is NOT numeric
Reference: http://php.net/manual/en/function.is-numeric.php