Operators

Operator	Example
Unary Operators	Negation -a, address-of &a, dereference *a
Binary Operators	Equality a==a, multiplication a*a
Ternary Operators	a ? b : c

boolean_condition ? this_if_bc_is_true : this_if_bc_is_false

Arithmetic Operators

Operator	Explanation
+a	unary plus
-a	unary minus
a + b
a - b
a * b
a / b
a % b	modulo
~a	bit-wise NOT
a & b	bit-wise AND
a	b
a ^ b	bit-wise XOR
a << b	bit-wise left shift
a >> b	bit-wise right shift

Undefined behavior occurs when

• signed overflow
• division by zero
• shift by negative offset
• shift by offset larger than the type’s width

Logical and relational operators

Operator	Explanation
!a	logical NOT
a && b	logical AND (short-circuiting)
a
a == b	equal to
a != b	not equal to
a < b	less than
a > b	greater than
a <= b	less than or equal to
a >= b	greater than or equal to

Assignment operators

Operator	Explanation
a = b	simple assignment
a += b	addition assignment (equal to a = a + b)
a -= b	subtraction assignment
a *= b	multiplication assignment
a /= b	division assignment
a %= b	modulo assignment
a &= b	bit-wise AND assignment
a	= b
a ^= b	bit-wise XOR assignment
a <<= b	bit-wise left shift assignment
a >>= b	bit-wise right shift assignment

• a must be an lvalue
• b can be lvalue or rvalue

int a,b,c;
a = b = c = 42;

int computeValue(){
    return 0;
}
if(int d = computeValue()){
    //Do something if d !=0
}
else{
    //Do something if d == 0
    //d is usable in both
}

LValue and RValue

• lvalue refers to an object’s identity
• rvalue refers to an object’s value

Increment / Decrement

Operator	Explanation
++a	prefix increment
–a	prefix decrement
a++	postfix increment
a–	postfix decrement

• Prefix
  • Increment the value of the object and return a reference to the result
• Postfix
  • Increment the value of the object, however return a copy of the original

Precedence	Operator	Description	Associativity
1	::	Scope resolution	Left-to-right →
2	a++   a--	Suffix/postfix increment and decrement
	type()   type{}	Functional cast
	a()	Function call
	a[]	Subscript
	.   ->	Member access
3	++a   --a	Prefix increment and decrement	Right-to-left ←
	+a   -a	Unary plus and minus
	!   ~	Logical NOT and bitwise NOT
	(type)	C-style cast
	*a	Indirection (dereference)
	&a	Address-of
	sizeof	Size-of[note 1]
	co_await	await-expression (C++20)
	new   new[]	Dynamic memory allocation
	delete   delete[]	Dynamic memory deallocation
4	.*   ->*	Pointer-to-member	Left-to-right →
5	a*b   a/b   a%b	Multiplication, division, and remainder
6	a+b   a-b	Addition and subtraction
7	<<   >>	Bitwise left shift and right shift
8	<=>	Three-way comparison operator (since C++20)
9	<   <=   >   >=	For relational operators < and ≤ and > and ≥ respectively
10	==   !=	For equality operators = and ≠ respectively
11	a&b	Bitwise AND
12	^	Bitwise XOR (exclusive or)
13	|	Bitwise OR (inclusive or)
14	&&	Logical AND
15	||	Logical OR
16	a?b:c	Ternary conditional[note 2]	Right-to-left ←
	throw	throw operator
	co_yield	yield-expression (C++20)
	=	Direct assignment (provided by default for C++ classes)
	+=   -=	Compound assignment by sum and difference
	*=   /=   %=	Compound assignment by product, quotient, and remainder
	<<=   >>=	Compound assignment by bitwise left shift and right shift
	&=   ^=   |=	Compound assignment by bitwise AND, XOR, and OR
17	,	Comma	Left-to-right →