Compact · Software Engineering Wiki

Removes zero values from a collection.

Use reflect.ValueOf() to get the array or slice, make() to make an appropriate slice.
Use a for loop with Value.Len() and Value.Index() to iterate over each element.
Use append() to add it to the resulting slice if Value.IsZero() is `false.

import "reflect"

func Compact(params ...interface{}) []reflect.Value {
	arr := reflect.ValueOf(params[0])
	r := make([]reflect.Value, 0)

	for i := 0; i < arr.Len(); i++ {
		if !arr.Index(i).IsZero() {
			r = append(r, arr.Index(i))
		}
	}
	return r
}

arr := []float64{1, 0, 5, 2}
arc := make([]float64, 0)
for _, v := range Compact(arr) {
  arc = append(arc, v.Float())
}
// arc = [1 5 2]