Go Keyword range

Internal

• Keywords
• for

Overview

range keyword is used to iterate over strings, arrays, slices, maps, channels and variadic function arguments. It returns two values. On the first position is the index/key, and on the second position is the copy of the value in that element.

Note that only a first identifier is declared, that is the index and not the value, as the intuition would suggest. See examples below.

Iterating over Indices

var a [5]int
for i := range a {
   // i is the index
}

Iterating over Values

var a [5]int
for _, value := range a {
   // 'value' is the value
}

Iterating over Indices and Values

var a [5]int
for i, value := range a {
   // i is the index
   // 'value' is the value
}

range and Channels

range