Mutable Map - Lo — ContextQMD

Transforms each element in the slice by applying the transform function in place. The length remains unchanged; values are overwritten in the same backing array.

Variants: MapI accepts an index-aware mapper (item T, index int) T.

import lom "github.com/samber/lo/mutable"

list := []int{1, 2, 3, 4}
lom.Map(list, func(x int) int {
    return x * 2
})
// list -> []int{2, 4, 6, 8}

Mapping strings:

words := []string{"go", "LoDash", "lo"}
lom.Map(words, func(s string) string {
    return strings.ToUpper(s)
})
// words -> []string{"GO", "LODASH", "LO"}

Index-aware variant (MapI):

nums := []int{10, 11, 12}
// add index to each number
lom.MapI(nums, func(x int, i int) int {
    return x + i
})
// nums -> []int{10, 12, 14}

vals := []string{"a", "b", "c", "d"}
lom.MapI(vals, func(s string, i int) string {
    if i%2 == 0 { return s + "!" }
    return s
})
// vals -> []string{"a!", "b", "c!", "d"}