Operator
- Operator Precedence
- Arithmetic Operators
- Assignment Operators
- Bitwise Operators
- Comparations Operators
- Ternary Operator
- Null Coalescing Operator
- Error Control Operators
- Execution Operators
- Increment and Decrement Operators
- Logical Operators
- String Operators
- Array Operators
- Type Operators
- Operators List
Operator Precedence
Option 1
$fahrenheit = 50;
$celsius = $fahrenheit - 32 / 1.8;
var_dump($celsius); //=> float(32.222222222222)
Option 2
// grouping operator
$fahrenheit = 50;
$celsius = ($fahrenheit - 32) / 1.8;
var_dump($celsius); //=> float(10)
Arithmetic Operators
// unary identity operator
$number = "15";
var_dump($number); //=> string(2) "15"
var_dump(+$number); //=> int(15)
// unary negation operator
$number = -15;
var_dump($number); //=> -15 11111111111111111111111111110001
var_dump(+$number); //=> 15 00000000000000000000000000001111
// addition operator
var_dump(10 + 3); //=> int(13)
var_dump("10" + 3); //=> int(13)
var_dump(true + 3); //=> int(4)
// subtraction operator
var_dump(10 - 3); //=> int(7)
var_dump(1.4 - 1.2); //=> float(0.2)
// multiplication operator
var_dump(10 * 3); //=> int(30)
// division operator
var_dump(10 / 3); //=> float(3.3333333333333)
var_dump((int) (10 / 3)); //=> int(3) - Integer division
var_dump(round(10 / 3)); //=> float(3) - Integer division
// remainder operator
var_dump(10 % 3); //=> int(1)
// exponentiation operator
var_dump(10 ** 3); //=> int(1000); before php 5.6: pow(10, 3)
Assignment Operators
// assign operator
$variable = 10;
var_dump($variable); //=> int(10)
Shorthand: +=, -=, *=, **=, /=, .=, %=, &=, |=, ^=, <<=, >>=
// addition assignment operator
$variable = 10;
$variable += 1; // $variable = $variable + 1
var_dump($variable;) //=> int(11)
Bitwise Operators
// bitwise and operator
var_dump(9); //=> 00000000000000000000000000001001 int(9)
var_dump(14); //=> 00000000000000000000000000001110 int(14)
var_dump(14 & 9); //=> 00000000000000000000000000000100 int(8)
// bitwise or operator
var_dump(9); //=> 00000000000000000000000000001001 int(9)
var_dump(14); //=> 00000000000000000000000000001110 int(14)
var_dump(14 | 9); //=> 00000000000000000000000000001111 int(15)
// bitwise xor operator
var_dump(9); //=> 00000000000000000000000000001001 int(9)
var_dump(14); //=> 00000000000000000000000000001110 int(14)
var_dump(14 ^ 9); //=> 00000000000000000000000000000101 int(7)
// bitwise not operator
$number = 16;
var_dump($number); //=> 00000000000000000000000000010000 int(16)
var_dump(~$number); //=> 11111111111111111111111111101111 int(-17)
// shitf left operator - each step means "multiply by two"
var_dump( 9 ); //=> 00000000000000000000000000001001 int(9)
var_dump( 9 << 2); //=> 00000000000000000000000000100100 int(36)
// right shift operator - each step means "divide by two"
var_dump( 9 ); //=> 00000000000000000000000000001001 9
var_dump( 9 >> 2); //=> 00000000000000000000000000000010 2
var_dump(-9 ); //=> 11111111111111111111111111110110 -9
var_dump(-9 >> 2); //=> 11111111111111111111111111111101 -3
Comparations Operators
// equality operator
var_dump(1 == 1); //=> bool(true)
var_dump(1 == "1"); //=> bool(true)
var_dump(1 == 2); //=> bool(false)
// inequality operator / not equal (<>, !=)
var_dump(1 <> 1); //=> bool(false)
var_dump(1 != 1); //=> bool(false)
var_dump(1 != "1"); //=> bool(false)
var_dump(1 != 2); //=> bool(true)
// identity/strict equality
var_dump(1 === 1); //=> bool(true)
var_dump(1 === "1"); //=> bool(false)
var_dump(1 === 2); //=> bool(false)
// non-identity
var_dump(1 !== 1); //=> bool(false)
var_dump(1 !== "1"); //=> bool(true)
var_dump(1 !== 2); //=> bool(true)
// less than operator
var_dump(1 < 10); //=> bool(true)
// greater than operator
var_dump(1 > 10); //=> bool(false)
// less than or equal operator
var_dump(1 <= 10); //=> bool(true)
// greater than or equal operator
var_dump(1 >= 10); //=> bool(false)
// spaceship operator
var_dump(1 <=> 0); //=> int(1)
var_dump(1 <=> 1); //=> int(0)
var_dump(0 <=> 1); //=> int(-1)
var_dump('fulano' <=> 'sicrano'); //=> int(-1)
var_dump('fulano' <=> 'Sicrano'); //=> int(1)
$a = (object) ["a" => "b"];
$b = (object) ["a" => "b"];
var_dump($a <=> $b); //=> int(0)
var_dump("1 programador"+"1 computador" == "2 passos para o paraíso"); //=> bool(true)
var_dump("1 programador"+"1 computador" === (int)"2 passos paraíso"); //=> bool(true)
References:
Ternary Operator
$number = 10;
$result = $number ? $number : 0;
var_dump($result); //=> int(10)
Null Coalescing Operator
$result = $number ?? 0;
var_dump($result); //=> int(0)
Error Control Operators
$values = [1, 2, 3];
$result = $values[3]; //=> PHP Notice: Undefined offset: 3
$values = [1, 2, 3];
$result = @$values[3];
var_dump($result); //=> NULL
Execution Operators
// pwd command
var_dump(`pwd`); //=> string(12) "/pasta_atual"
var_dump(exec('pwd')); //=> string(12) "/pasta_atual"
// ping command
var_dump(shell_exec('ping -c1 8.8.8.8'));
//=>
// string(249) "PING 8.8.8.8 (8.8.8.8): 56 data bytes
// 64 bytes from 8.8.8.8: icmp_seq=0 ttl=50 time=72.338 ms
//
// --- 8.8.8.8 ping statistics ---
// 1 packets transmitted, 1 packets received, 0.0% packet loss
// round-trip min/avg/max/stddev = 72.338/72.338/72.338/0.000 ms
// "
Increment and Decrement Operators
// postfix increment
$number = 10;
var_dump($number++); //=> int(10)
// prefix increment
$number = 10;
var_dump(++$number); //=> int(11)
// postfix decrement
$number = 10;
var_dump($number--); //=> int(10)
// prefix decrement
$number = 10;
var_dump(--$number); //=> int(9)
Logical Operators
// logical and operator (and, &&)
var_dump(true and true); //=> bool(true)
var_dump(true && true); //=> bool(true)
var_dump(true && 10); //=> bool(true)
var_dump(false && 10); //=> bool(false)
// logical or operator (or, ||)
var_dump(true or true); //=> bool(true)
var_dump(true || true); //=> bool(true)
var_dump(true || 10); //=> bool(true)
var_dump(false || 10); //=> bool(true)
// logical xor operator
var_dump(true xor true); //=> bool(false)
var_dump(true xor false); //=> bool(true)
var_dump(false xor 10); //=> bool(true)
var_dump(false xor false); //=> bool(false)
// logical not operator
var_dump(!true); //=> bool(false)
var_dump(!false); //=> bool(true)
var_dump(!10); //=> bool(false)
String Operators
$name = "Alice";
var_dump("Hello ".$name); //=> string(11) "Hello Alice"
Array Operators
// array union operator
var_dump([1] + [2, 3]);
//=>
// array(2) {
// [0]=> int(1)
// [1]=> int(3)
// }
// array equality operator
var_dump([1] == [1]); //=> bool(true)
var_dump([1] == ["1"]); //=> bool(true)
var_dump([1, 2] == [3]); //=> bool(false)
// array inequality operator / not equal (<>, !=)
var_dump([1] <> [1]); //=> bool(false)
var_dump([1] != [1]); //=> bool(false)
var_dump([1] != ["1"]); //=> bool(false)
var_dump([1, 2] != [3]); //=> bool(true)
// array identity/strict equality
var_dump([1] === [1]); //=> bool(true)
var_dump([1] === ["1"]); //=> bool(false)
var_dump([1, 2] === [3]); //=> bool(false)
// array non-identity
var_dump([1] !== [1]); //=> bool(false)
var_dump([1] !== ["1"]); //=> bool(true)
var_dump([1, 2] !== [3]); //=> bool(true)
Type Operators
Type casting: (int), (integer), (float), (string), (array), (object), (bool), (boolean)
var_dump((int) "10"); //=> int(10)
instanceof
class MyClass { }
class OtherClass { }
$a = new MyClass;
var_dump($a instanceof MyClass); //=> bool(true)
var_dump($a instanceof OtherClass); //=> bool(false)
Operators List
| Operator type | Operators |
|---|---|
| Grouping | () |
| Clone | clone |
| Instantiation | new |
| Array operators | [], +, ==, !=, <>, ===, !== |
| Increment and decrement | A++, A--, ++A, --A |
| Arithmetic operators | +, -, *, /, %, ** |
| Type operators | (int), (float), (string), (array), (object), (bool), instanceof |
| Bitwise operators | ~, &, |, ^, <<, >> |
| Logical operators | !, &&, and, ||, or, xor |
| Error Control | @ |
| String operator | . |
| Execution Operator | `` |
| Comparison operators | <, <=, >, >=, ==, !=, <>, ===, !==, <=>, ?? |
| Ternary operators | ?: |
| Assignment operators | =, +=, -=, *=, **=, /=, .=, %=, &=, |=, ^=, <<=, >>= |
Non-associative
clone, new, instanceof, <, <=, >, >=, ==, !=, ===, !==:
1 < 2 > 1; //=> PHP Parse error: syntax error, unexpected '>'