ts重点学习52-构造函数笔记

export default {}
// 构造函数
var myFunction = new Function("a", "b", "return a*b");
var x = myFunction(4, 3);
console.log(x);
// 递归函数
function sum(arr: number[], n: number):number {
  if(n <= 0) {
    return 0;
  }else {
    return sum(arr, n-1) + arr[n-1];
  }
}
// sum([2, 3, 4, 5], 2) + 4
// sum([2, 3, 4, 5], 1) + 3 + 4
// sum([2, 3, 4, 5], 0) + 2 + 3 + 4
// 0 + 2 + 3 + 4 = 9
let res = sum([2, 3, 4, 5], 3);
console.log(res);