Operators are used to perform operations on variables and values.
For example:
$num=10+20;//+ is the operator and 10,20 are operands
In the above example, + is the binary + operator, 10 and 20 are operands and $num is variable.
PHP divides the operators in the following groups:
- Arithmetic Operators
- Assignment Operators
- Bitwise Operators
- Comparison Operators
- Incrementing/Decrementing Operators
- Logical Operators
- String Operators
- Array Operators
- Conditional assignment operators
We can also categorize operators on behalf of operands. They can be categorized in 3 forms:
- Unary Operators: works on single operands such as ++, — etc.
- Binary Operators: works on two operands such as binary +, -, *, / etc.
- Ternary Operators: works on three operands such as “?:”.
PHP Arithmetic Operators
The PHP arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc.
| Operator | Name | Example | Explanation |
|---|---|---|---|
| + | Addition | $a + $b | Sum of operands |
| – | Subtraction | $a – $b | Difference of operands |
| * | Multiplication | $a * $b | Product of operands |
| / | Division | $a / $b | Quotient of operands |
| % | Modulus | $a % $b | Remainder of operands |
| ** | Exponentiation | $a ** $b | $a raised to the power $b |
PHP Assignment Operators
The PHP assignment operators are used with numeric values to write a value to a variable.
The basic assignment operator in PHP is “=”. It means that the left operand gets set to the value of the assignment expression on the right.
| Operator | Name | Example | Explanation |
|---|---|---|---|
| = | Assign | $a = $b | The value of right operand is assigned to the left operand. |
| += | Add then Assign | $a += $b | Addition same as $a = $a + $b |
| -= | Subtract then Assign | $a -= $b | Subtraction same as $a = $a – $b |
| *= | Multiply then Assign | $a *= $b | Multiplication same as $a = $a * $b |
| /= | Divide then Assign (quotient) |
$a /= $b | Find quotient same as $a = $a / $b |
| %= | Divide then Assign (remainder) |
$a %= $b | Find remainder same as $a = $a % $b |
PHP Bitwise Operators
The bitwise operators are used to perform bit-level operations on operands. These operators allow the evaluation and manipulation of specific bits within the integer.
| Operator | Name | Example | Explanation |
|---|---|---|---|
| & | And | $a & $b | Bits that are 1 in both $a and $b are set to 1, otherwise 0. |
| | | Or (Inclusive or) | $a | $b | Bits that are 1 in either $a or $b are set to 1 |
| ^ | Xor (Exclusive or) | $a ^ $b | Bits that are 1 in either $a or $b are set to 0. |
| ~ | Not | ~$a | Bits that are 1 set to 0 and bits that are 0 are set to 1 |
| << | Shift left | $a << $b | Left shift the bits of operand $a $b steps |
| >> | Shift right | $a >> $b | Right shift the bits of $a operand by $b number of places |
PHP Comparison Operators
The PHP comparison operators are used to compare two values (number or string):
| Operator | Name | Example | Explanation |
|---|---|---|---|
| == | Equal | $a == $b | Return TRUE if $a is equal to $b |
| === | Identical | $a === $b | Return TRUE if $a is equal to $b, and they are of same data type |
| !== | Not identical | $a !== $b | Return TRUE if $a is not equal to $b, and they are not of same data type |
| != | Not equal | $a != $b | Return TRUE if $a is not equal to $b |
| <> | Not equal | $a <> $b | Return TRUE if $a is not equal to $b |
| < | Less than | $a < $b | Return TRUE if $a is less than $b |
| > | Greater than | $a > $b | Return TRUE if $a is greater than $b |
| <= | Less than or equal to | $a <= $b | Return TRUE if $a is less than or equal $b |
| >= | Greater than or equal to | $a >= $b | Return TRUE if $a is greater than or equal $b |
| <=> | Spaceship | $a <=>$b | Return -1 if $a is less than $b Return 0 if $a is equal $b Return 1 if $a is greater than $b |
PHP Increment / Decrement Operators
- The PHP increment operators are used to increment a variable’s value.
- The PHP decrement operators are used to decrement a variable’s value.
| Operator | Name | Example | Explanation |
|---|---|---|---|
| ++ | Increment | ++$a | Increment the value of $a by one, then return $a |
| $a++ | Return $a, then increment the value of $a by one | ||
| — | decrement | –$a | Decrement the value of $a by one, then return $a |
| $a– | Return $a, then decrement the value of $a by one |
PHP Logical Operators
The PHP logical operators are used to combine conditional statements.
| Operator | Name | Example | Explanation |
|---|---|---|---|
| and | And | $a and $b | Return TRUE if both $a and $b are true |
| Or | Or | $a or $b | Return TRUE if either $a or $b is true |
| xor | Xor | $a xor $b | Return TRUE if either $ or $b is true but not both |
| ! | Not | ! $a | Return TRUE if $a is not true |
| && | And | $a && $b | Return TRUE if either $a and $b are true |
| || | Or | $a || $b | Return TRUE if either $a or $b is true |
PHP String Operators
PHP has two operators that are specially designed for strings.
| Operator | Name | Example | Explanation |
|---|---|---|---|
| . | Concatenation | $a . $b | Concatenate both $a and $b |
| .= | Concatenation and Assignment | $a .= $b | First concatenate $a and $b, then assign the concatenated string to $a, e.g. $a = $a . $b |
PHP Array Operators
The PHP array operators are used to compare arrays.
| Operator | Name | Example | Explanation |
|---|---|---|---|
| + | Union | $a + $y | Union of $a and $b |
| == | Equality | $a == $b | Return TRUE if $a and $b have same key/value pair |
| != | Inequality | $a != $b | Return TRUE if $a is not equal to $b |
| === | Identity | $a === $b | Return TRUE if $a and $b have same key/value pair of same type in same order |
| !== | Non-Identity | $a !== $b | Return TRUE if $a is not identical to $b |
| <> | Inequality | $a <> $b | Return TRUE if $a is not equal to $b |
PHP Conditional Assignment Operators
The PHP conditional assignment operators are used to set a value depending on conditions:
| Operator | Name | Example | Explanation |
|---|---|---|---|
| ?: | Ternary | $x = expr1 ? expr2 : expr3 | Returns the value of $x. The value of $x is expr2 if expr1 = TRUE. The value of $x is expr3 if expr1 = FALSE |
| ?? | Null coalescing | $x = expr1 ?? expr2 | Returns the value of $x. The value of $x is expr1 if expr1 exists, and is not NULL. If expr1 does not exist, or is NULL, the value of $x is expr2. Introduced in PHP 7 |
