PHP is_numeric() Function: Complete Guide

The is_numeric() function in PHP is used to check if a variable is a number or a numeric string. It returns true if the variable is a number or numeric string, otherwise it returns false.

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$var1 = 123;
$var2 = "456";
$var3 = "abc";

var_dump(is_numeric($var1)); // 输出true
var_dump(is_numeric($var2)); // 输出true
var_dump(is_numeric($var3)); // 输出false