In this PHP tutorial, you shall learn how to check if given string contains only numeric digits using preg_match() function, with example programs. PHP – Check if string contains only numeric digits To check if a string contains only numeric digits in PHP, callpreg_match()function and pass...
php function isStringBoolean($value) { // 将字符串转换为小写 $value = strtolower($value); // 检查字符串是否为"true"或"false" if ($value === 'true') { return true; } elseif ($value === 'false') { return false; } else { // 如果字符串不是"true"或"false",返回null表示不是布...
Check if a string is valid UUID: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 <?php use Ramsey\Uuid\Nonstandard\Uuid; require_once __DIR__.'/vendor/autoload.php'; function isValidUuid(string $value): bool { return Uuid::isValid($value); } $isValid = isValidUuid('5338d5e4...
1. Check if given string is a floating value In this example, we will take a string, whose value represents a floating point number, and verify programmatically if the string is a float or not using type conversion and equal to operator. PHP Program </> Copy <?php$string="3.14";$float...
php// Define a function that checks if the substring starting from the second position (index 1) is "yt"// If true, the function returns a modified string excluding the character at index 1// If false, the function returns the original stringfunctiontest($s){returnsubstr($s,1,2)=="...
It uses substr to get the ending part of the string that’s the same length as the substring, then checks if it’s equal to the substring. It’s useful for checking if a string has a certain ending, like a file extension. PHP Function: function endsWith($str, $substr) { return ...
Requires PHP versions 5.3 or more. function isJSON($string){ return is_string($string) && is_array(json_decode($string, true)) && (json_last_error() == JSON_ERROR_NONE) ? true : false; } Method 2 does 3 checks for calculating if the string given to it is JSON. So, it is the...
(PHP 4 >= 4.4.3, PHP 5 >= 5.1.3, PHP 7) mb_check_encoding — Check if the string is valid for the specified encoding mb_check_encoding — 检查字符串在指定的编码里是否有效 Description boolmb_check_encoding([string$var=NULL[,string$encoding=mb_internal_encoding() ]] )// Checks if...
c# Check registry if program is installed if yes get install location ? C# Check to make sure first character in a string is a letter C# check username if already exists from database C# Class - USB Port Enabled/Disabled Status Detection C# class for JSON is resulting a Null Reference E...
0x2603 for U+2603 SNOWMAN), or the character encoded as a UTF-8 string (e.g. "\u{2603}") 返回值 Returns TRUE if codepoint is a hexadecimal character, FALSE if not. 注释 Note: In order to narrow the definition of hexadecimal digits to only ASCII characters use: <?php$isASCII...