实现二维数组元素两两组合

代码实现：给一个数组如：[[“a”,”b”,”c”],[“d”,”e”],…..]得到[ad,ae,bd,be,cd,ce]

(function () {
      let a = [[1, 2, 3, 4, 5], [a, b, d], [6, 7, 8, 9], [a, s, d, w], [11, 12, 13, 14, 15]]
      let result = []
      for (let i = 0; i < a.length; i++) {
        for (let j = 0; j < a[i].length; j++) {
          for (let k = i + 1; k < a.length; k++) {
            for (let l = 0; l < a[k].length; l++) {
              result.push(a[i][j] + '-' + a[k][l])
            }
          }
        }
      }
      console.log(result)
      return result
    })()