30秒学会 Golang 片段 – XProduct

Creates a new slice out of the two supplied by creating each possible pair from the collections.

Use reflect.ValueOf() to get the arrays or slices, Value.Len() and make() to create an appropriate slice for the result.
Use a for loop with Value.Len(), Value.Index() and Value.Interface() to populate the result.

代码实现

import "reflect"

func XProduct(params ...interface{}) [][]interface{} {
    a, b := reflect.ValueOf(params[0]), reflect.ValueOf(params[1])
    l := a.Len() * b.Len()
    r := make([][]interface{}, l)

    for i := 0; i < l; i++ {
        r[i] = []interface{}{
            a.Index(i % a.Len()).Interface(),
            b.Index((i / a.Len()) % b.Len()).Interface(),
        }
    }
    return r

}

使用样例

XProduct([]int{1, 2}, []string{"a", "b"}) // [[1 a] [2 a] [1 b] [2 b]]