Go array initialization

Question

func identityMat4() [16]float {
    return {
        1, 0, 0, 0,
        0, 1, 0, 0,
        0, 0, 1, 0,
        0, 0, 0, 1 }
}

I hope you get the idea

Answer 1

func identityMat4() [16]float64 {
    return [...]float64{
        1, 0, 0, 0,
        0, 1, 0, 0,
        0, 0, 1, 0,
        0, 0, 0, 1 }
}

(Click to play)

Answer 2

If you were writing your program using Go idioms, you would be using slices. For example,

package main

import "fmt"

func Identity(n int) []float {
    m := make([]float, n*n)
    for i := 0; i < n; i++ {
        for j := 0; j < n; j++ {
            if i == j {
                m[i*n+j] = 1.0
            }
        }
    }
    return m
}

func main() {
    fmt.Println(Identity(4))
}

Output: [1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1]

Answer 3

How to use an array initializer to initialize a test table block:

tables := []struct {
    input []string
    result string
} {
    {[]string{"one ", " two", " three "}, "onetwothree"},
    {[]string{" three", "four ", " five "}, "threefourfive"},
}

for _, table := range tables {
    result := StrTrimConcat(table.input...)

    if result != table.result {
        t.Errorf("Result was incorrect. Expected: %v. Got: %v. Input: %v.", table.result, result, table.input)
    }
}

Answer 4

s := []int{5, 2, 6, 3, 1, 4} // unsorted
sort.Ints(s)
fmt.Println(s)