Go: Operators

See Operator precedence for evaluation order.

Arithmetic

Operator   Name                 Types
--------   ----                 -----
+          sum                  integers, floats, complex values, strings
-          difference           integers, floats, complex values
*          product              integers, floats, complex values
/          quotient             integers, floats, complex values

%          remainder            integers
&          bitwise AND          integers
|          bitwise OR           integers
^          bitwise XOR          integers
&^         bit clear (AND NOT)  integers

<<         left shift           integer << unsigned integer
>>         right shift          integer >> unsigned integer

See Arithmetic operators in the Go language specification for complete definitions of the shift, quotient and remainder operators, integer overflow, and floating point behavior.

Comparison

Comparison operators compare two operands and yield an untyped boolean value.

Operator   Name                 Types
--------   ----                 -----
==         equal                comparable
!=         not equal            comparable

<          less                 integers, floats, strings
<=         less or equal        integers, floats, strings
>          greater              integers, floats, strings
>=         greater or equal     integers, floats, strings
  • Boolean, integer, floats, complex values and strings are comparable.
  • Strings are ordered lexically byte-wise.
  • Two pointers are equal if they point to the same variable or if both are nil.
  • Two channel values are equal if they were created by the same call to make or if both are nil.
  • Two interface values are equal if they have identical dynamic types and equal concrete values or if both are nil.
  • A value x of non-interface type X and a value t of interface type T are equal if t’s dynamic type is identical to X and t’s concrete value is equal to x.
  • Two struct values are equal if their corresponding non-blank fields are equal.
  • Two array values are equal if their corresponding elements are equal.

Logical

Logical operators apply to boolean values. The right operand is evaluated conditionally.

Operator   Name              Description
--------   ----              -----------
&&         conditional AND   p && q  denotes  "if p then q else false"
||         conditional OR    p || q  denotes  "if p then true else q"
!          NOT               !p      denotes  "not p"

Others

Operator   Name                  Description
--------   ----                  -----------
&          address of            &x generates a pointer to x
*          pointer indirection   *x denotes the variable pointed to by x
<-         receive               <-ch is the value received from channel ch

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