How to determine whether a variable is a number in php

php method to determine whether a variable is a number: 1. Use the "gettype($var)" statement. If the return value is "integer" or "double", it is a number; 2. Use "is_numeric($var) )" statement, if the return value is "TRUE" it is a number and a numeric string.

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

php judgment variable is Not a number

Method 1: Use the gettype() function

<?php
header("Content-type:text/html;charset=utf-8");
$num=123.25;
if(gettype($num)=="integer"||gettype($num)=="double"){
	echo "是数字";
}else{
	echo "不是数字";
}
?>

Output result:

是数字

Instructions: The gettype() function is used to get the type of a variable. The return value can be:

• boolean

• integer

• ##double (Since PHP 4, if it is a float, it will return "double" instead of "float")

• #string

• array

• object

• resource (resource)

  resource is a special variable type that saves a reference to an external resource; it mainly Describes a PHP extension resource. Resources are created and used through specialized functions.

  
  

• NULL

  NULL is also a special data type. It has only one value, NULL, which means a null value (i.e. The variable has no value).

  
  

• unknown type

##Method 2: Use is_numeric() function

Detect whether the variable $var is a number or a numeric string. If $var is, return TRUE, otherwise return FALSE; syntax "

is_numeric($var)

". <pre class="brush:php;toolbar:false">&lt;?php header(&quot;Content-type:text/html;charset=utf-8&quot;); $num=123; if(is_numeric($num)){ echo &quot;是数字&quot;; }else{ echo &quot;不是数字&quot;; } ?&gt;</pre>Output result:

是数字

Recommended learning: "

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