C++ Programming: Language Default Operators

Table of operatorsEdit

Operators in the same group have the same precedence and the order of evaluation is decided by the associativity (left-to-right or right-to-left). Operators in a preceding group have higher precedence than those in a subsequent group.

Binding of operators actually cannot be completely described by "precedence" rules, and as such this table is an approximation. Correct understanding of the rules requires an understanding of the grammar of expressions.

Operators Description Example Usage Associativity
Scope Resolution Operator
:: unary scope resolution operator
for globals
:: binary scope resolution operator
for class and namespace members

Function Call, Member Access, Post-Increment/Decrement Operators, RTTI and C++ Casts Left to right
() function call operator swap (x, y)
[] array index operator arr [i]
. member access operator
for an object of class/union type
or a reference to it
-> member access operator
for a pointer to an object of
class/union type
++ -- post-increment/decrement operators num++
typeid() run time type identification operator
for an object or type
typeid (std::cout)
typeid (std::iostream)
C++ style cast operators
for compile-time type conversion
See Type Casting for more info
static_cast<float> (i)
dynamic_cast<std::istream> (stream)
const_cast<char*> ("Hello, World!")
reinterpret_cast<const long*> ("C++")
type() functional cast operator
(static_cast is preferred
for conversion to a primitive type)
float (i)
also used as a constructor call
for creating a temporary object, esp.
of a class type
std::string ("Hello, world!", 0, 5)

Unary Operators Right to left
!, not logical not operator !eof_reached
~, compl bitwise not operator ~mask
+ - unary plus/minus operators -num
++ -- pre-increment/decrement operators ++num
&, bitand address-of operator &data
* indirection operator *ptr
new operators
for single objects or arrays
new std::string (5, '*')
new int [100]
new (raw_mem) int
new (arg1, arg2) int [100]
delete operator
for pointers to single objects or arrays
delete ptr
delete[] arr
sizeof operator
for expressions or types
sizeof 123
sizeof (int)
(type) C-style cast operator (deprecated) (float)i

Member Pointer Operators Right to left
.* member pointer access operator
for an object of class/union type
or a reference to it
->* member pointer access operator
for a pointer to an object of
class/union type

Multiplicative Operators Left to right
* / % multiplication, division and
modulus operators
celsius_diff * 9 / 5

Additive Operators Left to right
+ - addition and subtraction operators end - start + 1

Bitwise Shift Operators Left to right
left and right shift operators bits << shift_len
bits >> shift_len

Relational Inequality Operators Left to right
< > <= >= less-than, greater-than, less-than or
equal-to, greater-than or equal-to
i < num_elements

Relational Equality Operators Left to right
== !=, not_eq equal-to, not-equal-to choice != 'n'

Bitwise And Operator Left to right
&, bitand bits & clear_mask_complement

Bitwise Xor Operator Left to right
^, xor bits ^ invert_mask

Bitwise Or Operator Left to right
|, bitor bits | set_mask

Logical And Operator Left to right
&&, and arr != 0 && arr->len != 0

Logical Or Operator Left to right
||, or arr == 0 || arr->len == 0

Conditional Operator Right to left
?: size >= 0 ? size : 0

Assignment Operators Right to left
= assignment operator i = 0
+= -= *= /= %=
&=, and_eq
|=, or_eq
^=, xor_eq <<= >>=
shorthand assignment operators
(foo op= bar represents
foo = foo op bar)
num /= 10

throw throw "Array index out of bounds"

Comma Operator Left to right
, i = 0, j = i + 1, k = 0

Last modified on 21 April 2012, at 11:04