Detailed explanation of the use of PHP Boolean value auto-increment and auto-decrement-PHP Tutorial-php.cn

Detailed explanation of the use of PHP Boolean value auto-increment and auto-decrement

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Release： 2023-03-25 21:10:01

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This time I will bring you a detailed explanation of the use of PHP Boolean values for self-increment and self-decrement. What are the precautions for using PHP Boolean values for self-increment and self-decrement? The following is a practical case, let’s take a look. .

He discovered that PHP’s Boolean value is incremented. No matter how many times it is incremented, the final output is 1

This is more interesting~

Self-increment and self-decrement, everyone knows the difference between $a and $a

a means to take the address of a, increase the value of a in the memory, and then put the value in the register

a means taking the address of a, loading the value of a into the register, and then increasing the value of a in the memory

I opened an

editor to confirm the result

$a = true;
var_dump(--$a);
echo PHP_EOL;
echo $a;
$b = false;
echo PHP_EOL;
var_dump(++$b);

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The final input result of the operation is as follows

bool(true)
1
bool(false)

Copy after login

It is found that the result is not quite right as expected before. PHP does not do any processing for the auto-increment operation of Boolean values, and after the auto-increment is 1 is because we used echo to output, resulting in bool being forced to

to query the official documentation of PHP. Unexpectedly, there was an obvious line of prompts

Note:

increment/decrement Operator does not affect boolean values. Decrementing a NULL value has no effect, but increasing NULL results in 1.

# I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!