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65 lines
1.3 KiB
Markdown
65 lines
1.3 KiB
Markdown
+++
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title = "Comparisons"
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description = "Equality checking"
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tags = ["php", "comparisons"]
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slug = "comparisons"
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previous = "strings.html"
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next = "boolean-logic.html"
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+++
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A boolean is a value that is always 0 or 1, yes or no, on or off.
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In PHP, a boolean is represented by the words true and false.
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While programming, you will often want to know if something is positive or negative.
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```php
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<?php
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$a = true;
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$b = false;
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```
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There are many constructs and functions that will return a boolean.
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To start, let's look at comparisons.
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Double equals checks if two values are equal.
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```php
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$one = 1;
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$two = 2;
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$one == $two; // returns false
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```
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An exclamation point and equal sign check if two values are not equal.
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```php
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$one != $two; // returns true
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```
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You can use greater than and less than symbols to check for comparisons too.
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```php
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$one > $two; // returns false
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$one < $two; // returns true
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```
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If you combine a greater than or less than symbol with an equal,
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it will check if the value is greater or less than or equal to another value.
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```php
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$one <= $two;
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$one >= $two;
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```
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You can also check that two values are equal and of the same type
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by using three equal signs.
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The following comparisons return true.
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```php
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1 == 1;
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1 == '1';
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1 == true;
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1 == 1.0;
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1 === 1;
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```
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These return false.
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```php
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1 === '1';
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1 === true;
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1 === 1.0;
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```
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