is_numeric in php

How to Check a Value Is Numeric in PHP

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Definition and Usage of is_numeric in PHP

The is_numeric() function describes whether a variable is a number or a string of numbers.

If the variable is a number or a numeric string, this function returns true; otherwise, it returns false/nothing.

Additionally, based on the PHP documentation, is_numeric finds whether a variable is a number or a numeric string.

Syntax:

is_numeric( variable );

Parameter Values

ParameterDescription
variableRequired. Specifies the variable to check

Technical Details

Return Value:TRUE if variable is a number or a numeric string, FALSE otherwise
Return Type:Boolean
PHP Version:4.0+

Is_numeric PHP examples

The following is an example usage of is_numeric:

<?php
    // if it is a number
    $str = "050122";
    if ( is_numeric($str) ) {
        echo "'{$str}' is a numeric.";
    } else {
        echo "'{$str}' is not a numeric.";
    }
    
    echo ("\n");
    
    // if it is a string
    $str = "itsourcecode";
    if ( is_numeric($str) ) {
        echo "'{$str}' is a numeric.";
    } else {
        echo "'{$str}' is not a numeric.";
    }
?>

Output:

'050122' is a numeric.
'itsourcecode' is not a numeric.

Explanation:

The example above illustrates that if the value of a $str value is a number, it will print that it is numeric.

If it is a string, then it will print that it is not numeric.

Is_numeric PHP examples with whitespace

The following is an example usage of is_numeric, but this time, the value of the string has whitespace:

<?php
    // if it is a number
    $str = "05 01 22";
    if ( is_numeric($str) ) {
        echo "'{$str}' is a numeric.";
    } else {
        echo "'{$str}' is not a numeric.";
    }
    
    echo ("\n");
    
    // if it is a string
    $str = "it source code";
    if ( is_numeric($str) ) {
        echo "'{$str}' is a numeric.";
    } else {
        echo "'{$str}' is not a numeric.";
    }
?>

Output:

'05 01 22' is not a numeric.
'it source code' is not a numeric.

Explanation:

The example above illustrates that if the value of a $str value is a number with whitespace, it will print that it is not numeric.

Therefore, if the variable value has whitespace on it, it will return a value of False.

Frequently Ask Question

What is_numeric value in PHP?

PHP has a lot of built-in functions that can be used to check the type of data in a variable.

One of them is called is numeric(). It is used to see if a variable or a string of numbers is a number or a number.

Along with the digits, the string of numbers can have the “+/-” symbol, a decimal point, and an exponential part.

This tutorial shows how this function can be used for different things in PHP.

Is_numeric array PHP?

With a numeric array, we can store more than one value of the same type in a single variable instead of making a new variable for each value.

The index, which is always a number in a numeric array, can then be used to get to these values.

Note: The index always starts at 0 by default.

Is a function numeric?

Returns a Boolean value that says whether an expression can be evaluated as a number.

The required expression argument is a Variant with a string or numeric expression.

Summary

To summarize, we now understand exactly how to use is_numeric.

I hope this tutorial has helped you understand the meaning and application of is_numeric in PHP.

Lastly, if you want to learn more about is_numeric in PHP, please leave a comment below. We’ll be happy to hear it!

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