The difference between = and == in php

In PHP, = and == are different operators. = is used to assign a value and returns the assigned value, while == is used to compare whether two values ​​are equal and return a Boolean value. == is type-sensitive, = is not.

##The difference between = and == in PHP

= and == are two different operators with different uses and meanings.

= Operator

• Assignment Operator: is used to assign a value to a variable.
• Syntax: $variable = value;
• Example: $name = 'John';

== Operator

• Equality comparison operator: is used to compare whether two values ​​are equal.
• Syntax: $value1 == $value2;
• Example: if ($name == 'John') {

Difference

• Function: = is used for assignment and == is used for comparison.
• Operation results: = returns the assigned value, while == returns a Boolean value (true or false).
• Type Sensitivity: == is type sensitive, which means it takes into account the type of the value, while = does not.

Type sensitivity

When comparing two variables of different types,
• == will convert them to Same type and compare.
• = The type will not be converted and the original type will be maintained during allocation.

Example:

<code class="php">$number = 10;
$string = '10';

if ($number == $string) {
  echo 'Equal'; // 输出 "Equal"
}

if ($number = $string) {
  echo 'Equal'; // 错误，意外的分配
}</code>

== is converted to the same type (string), while in the first example = in both examples will cause allocation errors.

When to use

When you need to assign a value, use
• =.
When you need to compare two values ​​for equality, use
• ==.

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