In this tutorial you will learn about the Swift Operator Precedence and its application with practical example.
Swift Operator Precedence
Operator precedence defines the order in which given mathematical expression is evaluated. When an expression includes multiple operators then each of the single part of given expression is evaluated in a certain order following some rules defined as per operator precedence.Operator with higher precedence is evaluated first and operator with lowest precedence is evaluated at last.
Following is swift operator precedence table –
| Operator Groups | Examples |
|---|---|
| Bitwise shift precedence | >> &<< &>> >> |
| Multiplication precedence | &* % & * / |
| Addition precedence | | &+ &- + – ^ |
| Range Formation Precedence | ..< … |
| Casting Precedence | is as |
| Nil-Coalescing Precedence | ?? |
| Comparison Precedence | != > < >= <= === == |
| Logical Conjunction Precedence | && |
| Logical Disjunction Precedence | || |
| Default Precedence | ~> |
| Ternary Precedence | ?: |
| Function Arrow precedence | ( ) |
| Assignment Precedence | |= %= /= &<<= &>>= &= *= >>= <<= ^= += -= |
Operator Associativity
Operators with same precedence follows operator associativity defined for its operator group. In Swift, operators can either follow left-associative, right-associative or have no associativity. Operators with left-associative are evaluated from the left to right, operators with right-associative are evaluated from right to the left and operators with no associativity, does not follow any predefined order.
| Operator Groups | Examples | Associativity |
|---|---|---|
| Bitwise shift precedence | >> &<< &>> >> | none |
| Multiplication precedence | &* % & * / | left |
| Addition precedence | | &+ &- + – ^ | left |
| Range Formation Precedence | ..< … | none |
| Casting Precedence | is as | none |
| Nil-Coalescing Precedence | ?? | right |
| Comparison Precedence | != > < >= <= === == | none |
| Logical Conjunction Precedence | && | left |
| Logical Disjunction Precedence | || | left |
| Default Precedence | ~> | none |
| Ternary Precedence | ?: | right |
| Function Arrow precedence | ( ) | right |
| Assignment Precedence | |= %= /= &<<= &>>= &= *= >>= <<= ^= | right |
