PHP determines whether a string is a number

php determines whether a string is a number

is_numeric() function is used to detect whether a variable is a number or a number String.

PHP version requirements: PHP 4, PHP 5, PHP 7

Syntax

bool is_numeric ( mixed $var )

Parameter description:

$var: The variable to be tested.

Return value

Returns TRUE if the specified variable is a number or numeric string, otherwise returns FALSE.

Example:

<?php
$var_name1=678;

if (is_numeric($var_name1))
{
    echo "$var_name1 是数字" . PHP_EOL;
}
else
{
    echo "$var_name1 不是数字" . PHP_EOL ;
}

Output:

678 是数字

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