Home Backend Development PHP Tutorial The usage and difference between intval() and (int) conversion under PHP

The usage and difference between intval() and (int) conversion under PHP

Jun 06, 2018 am 11:19 AM
int intval

This article mainly introduces the use and difference between intval() and (int) conversion under PHP. It has a certain reference value. Now I share it with everyone. Friends in need can refer to it

Want to know What is the difference between using intval() and (int) conversion? Or what are the differences between the two, including functions and definitions. Or related to frequency of use, efficiency, etc.

Copy code The code is as follows:

<?php 
echo "<br/>数值强制转换:"; 
$string="2a"; 
$string1=intval($string); 
echo &#39;$string1的值:&#39;.$string1.&#39;$string2的值:&#39;;//单引号不会输出变量,将原样输出 
$string2=(int)($string); 
echo $string2 
?>
Copy after login

Can’t be found in the manual.
This is also what the manual says: Quote:
int intval (mixed $var [, int $base ])
By using a specific base conversion (the default is decimal), return the integer value of the variable var . If there is only this difference, then I like to use (int) to deal with decimal situations. Is it a good choice?
No difference, generally use (int), there are also float, string, array, etc.
In terms of intval(), if the parameter is a string, the first value in the string is returned. The integer value represented by the string of digits preceding a character that is not a digit. If the first character in the string is ‘-’, counting starts from the second character.
If the parameter is a dotted number, return its rounded value.
Of course, the value returned by intval() is within the range that can be represented by a 4-byte value (-2147483648~2147483647). Values ​​exceeding this range will be replaced by boundary values.
Example:

intval("A")=0; intval(12.3223)=12; intval("1123Asdfka3243")=1123; 
int();
Copy after login

Example:

$a=0.13; 
$b=(int)$a; //$b=0; 
$a=0.99; 
$b=(int)$a; //$b=0; 
$a=1.01; 
$b=(int)$a; //$b=1; 
$a=1.99; 
$b=(int)$a; //$b=1;
Copy after login

Convert PHP string to int
Sometimes, it is important to have a variable in int format value. eaxmple, if your visitor fills out the form with the age field, this should be an int. However, in the $_POST array, you are getting it as a string.
Converting a PHP string to int is easy. We need to use your variable type before casting.So you need to use (INT). Here is an example how to do this:

Copy code The code is as follows:

<?php $str = "10"; $num = (int)$str;?>
Copy after login

If you want to check that the code REALY works, we can use = == operator. This operator checks not only the value, but the type as well. Such code should look like this:

Copy code The code is as follows:

<?php 
$str = "10"; 
$num = (int)$str; 
if ($str === 10) echo "String"; 
if ($num === 10) echo "Integer"; 
?>
Copy after login

There is also an issue open. What happens if our string is not simply a string of numbers. I mean there are other characters in the string. In this case, the conversion operation tries the best and can convert the string if only space is there and if there are no valid characters after the numeric value. Its working principle is as follows:

“10” - > 10 
“10.5” - > 10 
“10,5” - > 10 
“10” - > 10 
“10” - > 10 
“10test” - > 10 
“test10” - > 0
Copy after login

Related recommendations: Comparative analysis of file_get_contents and curl performance in

php

The above is the detailed content of The usage and difference between intval() and (int) conversion under PHP. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Detailed explanation of the method of converting int type to bytes in PHP Detailed explanation of the method of converting int type to bytes in PHP Mar 06, 2024 pm 06:18 PM

Detailed explanation of the method of converting int type to byte in PHP In PHP, we often need to convert the integer type (int) to the byte (Byte) type, such as when dealing with network data transmission, file processing, or encryption algorithms. This article will introduce in detail how to convert the int type to the byte type and provide specific code examples. 1. The relationship between int type and byte In the computer field, the basic data type int represents an integer, while byte (Byte) is a computer storage unit, usually 8-bit binary data

C++ program to convert double type variable to int type C++ program to convert double type variable to int type Aug 25, 2023 pm 08:25 PM

In C++, variables of type int can only hold positive or negative integer values; they cannot hold decimal values. There are float and double values ​​available for this purpose. The double data type was created to store decimals up to seven digits after the decimal point. Conversion of an integer to a double data type can be done automatically by the compiler (called an "implicit" conversion), or it can be explicitly requested by the programmer from the compiler (called an "explicit" conversion). In the following sections, we'll cover various conversion methods. Implicit conversions The compiler performs implicit type conversions automatically. To achieve this, two variables are required - one of floating point type and the other of integer type. When we simply assign a floating point value or variable to an integer variable, the compiler takes care of all the other things

What is the value range of int32? What is the value range of int32? Aug 11, 2023 pm 02:53 PM

The value range of int32 is from -2 to the 31st power to 2 to the 31st power minus 1, that is, -2147483648 to 2147483647. int32 is a signed integer type, which means it can represent positive numbers, negative numbers, and zero. It uses 1 bit to represent the sign bit, and the remaining 31 bits are used to represent the numerical value. Since one bit is used to represent the sign bit, the effective number of int32 bits is 31.

How to convert int to string type in go language How to convert int to string type in go language Jun 04, 2021 pm 03:56 PM

Conversion method: 1. Use the Itoa() function, the syntax "strconv.Itoa(num)"; 2. Use the FormatInt() function to convert int type data into the specified base and return it in the form of a string, the syntax "strconv .FormatInt(num,10)".

How many bytes does int occupy? How many bytes does int occupy? Jan 22, 2024 pm 03:14 PM

The number of bytes occupied by the int type may vary in different programming languages ​​and different hardware platforms. Detailed introduction: 1. In C language, the int type usually occupies 2 bytes or 4 bytes. In 32-bit systems, the int type occupies 4 bytes, while in 16-bit systems, the int type occupies 2 bytes. In a 64-bit system, the int type may occupy 8 bytes; 2. In Java, the int type usually occupies 4 bytes, while in Python, the int type has no byte limit and can be automatically adjusted, etc.

How many numbers does java int have? How many numbers does java int have? Mar 06, 2023 pm 04:09 PM

In Java, int is a 32-bit signed data type, and its variables require 32-bit memory; the valid range of the int data type is -2147483648 to 2147483647, and all integers in this range are called integer literals. An integer literal can be assigned to an int variable, such as "int num1 = 21;".

How many bytes does int occupy? How many bytes does int occupy? Aug 11, 2023 pm 02:46 PM

int occupies 4 bytes, which means that an int variable can store an integer value ranging from -2,147,483,648 to 2,147,483,647. In some cases, it may also be 2 bytes or 8 bytes. Int is a commonly used Data types are used to represent integers. The appropriate data type needs to be selected according to the specific situation to ensure the correctness and performance of the program.

What does int mean in vb What does int mean in vb Dec 03, 2020 am 09:48 AM

Int in VB refers to a function that takes an integer. Its syntax is such as "int(x)", which means taking the largest integer not greater than x; functions similar to the int function include the Fix function, which deletes the decimal part and returns the remainder. the next integer.

See all articles