How to determine whether it is a string in php

In PHP, you can use the "is_string" function to determine whether a variable is a string. It can be understood that this function only detects the type. Even if a variable is empty, as long as it is a string type, it will return true. Its usage syntax is "bool is_string (mixed $var)".

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is_string() detects whether the variable is of string type and returns the value Is true or false. It can be understood here that it only detects the type. Even if a variable is empty, it will return true as long as it is a string type.

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

Syntax

bool is_string ( mixed $var )

Parameter description:

$var: Variable to be detected.

Return value

If the specified variable is a string, TRUE is returned, otherwise FALSE is returned.

Example

<?php
if (is_string("2663"))
    echo &#39;这是一个字符串。&#39; . PHP_EOL;
else
    echo &#39;这不是一个字符串。&#39;;
var_dump(is_string(&#39;XYZ&#39;));
var_dump(is_string("99"));
var_dump(is_string(123.05));
var_dump(is_string(false));
?>

The output result is:

This is a string.

bool(true)
bool(true)
bool(false)
bool(false)

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