PHP weak type (2)

PHP weak type (2)

3.intval() function

The intval() function is used to get the integer part of the variable, in the following part of the code:

<?php
	$uid = $_GET['uid'];
	if ($uid == "1")
	{
    
    
	 	$uid = intval($uid);
	 	$query = "SELECT * FROM 'users' WHERE uid=$uid;";
	}
	$result = mysql_query($query)
	print_r(mysql_fetch_row($result));
	

When uid=0.9999999999999999 is a long floating point number, the code logic will enter the if statement to query the user information with uid=0.

Output result:

4. Array comparison:

In_array() and array_seach() functions, if the $strict parameter is not set to true, loose comparison will be used. (The default setting is false)

<?php
	$array = [0,1,2,'3'];
	var_dump(in_array('abc', $array)); // true
	var_dump(array_search('abc', $array)); // 下标为0
	var_dump(in_array('1abc', $array)); // true
	var_dump(array_search('1abc', $array));// 下标为1