mirror of
https://github.com/restoreddev/phpapprentice.git
synced 2025-10-25 03:46:05 +02:00
65 lines
1.2 KiB
Markdown
65 lines
1.2 KiB
Markdown
A boolean is a value that is always 0 or 1, yes or no, on or off.
|
|
In PHP, a boolean is represented by the words true and false.
|
|
While programming, you will often want to know if something is positive or negative.
|
|
```php
|
|
<?php
|
|
|
|
$a = true;
|
|
$b = false;
|
|
```
|
|
|
|
There are many constructs and functions that will return a boolean.
|
|
To start, let's look at comparisons.
|
|
```php
|
|
$one = 1;
|
|
$two = 2;
|
|
```
|
|
|
|
Double equals checks if two values are equal.
|
|
This statement will return false.
|
|
```php
|
|
$one == $two;
|
|
```
|
|
|
|
An exclamation point and equal sign check if two values are not equal.
|
|
This statement will return true.
|
|
```php
|
|
$one != $two;
|
|
```
|
|
|
|
You can use greater than and less than symbols to check for comparisons too.
|
|
This statement will return false.
|
|
```php
|
|
$one > $two;
|
|
```
|
|
|
|
This statement will return true.
|
|
```php
|
|
$one < $two;
|
|
```
|
|
|
|
If you combine a greater than or less than symbol with an equal,
|
|
it will check if the value is greater or less than or equal to another value.
|
|
```php
|
|
$one <= $two;
|
|
$one >= $two;
|
|
```
|
|
You can also check that two values are equal and of the same type
|
|
by using three equal signs.
|
|
|
|
The following comparisons return true.
|
|
```php
|
|
1 == 1;
|
|
1 == '1';
|
|
1 == true;
|
|
1 == 1.0;
|
|
1 === 1;
|
|
```
|
|
|
|
These return false.
|
|
```php
|
|
1 === '1';
|
|
1 === true;
|
|
1 === 1.0;
|
|
```
|