How to convert positive integer to negative number in php

php method to convert an integer to a negative number: 1. Multiply the positive integer by negative 1, syntax "$num*(-1)"; 2. Use the "~" bit operator to invert the positive integer Add one to get the complement of a negative number, the syntax is "~$num 1".

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

php will convert positive integers Convert to negative number

The first way (supports decimals)

<?php
function f($num){
if($num>0){
$num=$num*(-1);
}
return $num;
}
echo f(100);
?>

Output:

The second method (decimals are not supported)

<?php
header("Content-type:text/html;charset=utf-8");
function f($num){
	return ~$num + 1;
}
echo f(200);
?>

Output:

Add the inverse of positive numbers After that, we get the complement of the negative number. The negative number is stored in the memory in the form of complement. When the complement is converted into the original code, it is the corresponding negative number after the positive number is converted.

After taking the inverse of the negative number and adding one, Get a complement code, but the original code of the positive number's complement is the same

Note: Negation and complementation are two different concepts. During the operation, the two's complement form is involved in the operation because there are negative numbers involved

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of How to convert positive integer to negative number in php. For more information, please follow other related articles on the PHP Chinese website!