Apply nested loops to calculate sum of products

by krui027

JavaScript

function testLoops(outer, inner, label) {
  console.time(label);
  let sum = 0;
  for (let i = 0; i < outer; i++) {
    for (let j = 0; j < inner; j++) {
      sum += i * j;
    }
  }
  console.timeEnd(label);
  return sum; // 防止引擎优化掉循环
}

const big = 1_000_000;  // 大次数
const small = 100;      // 小次数

// 情况A：大的次数在外层
testLoops(big, small, "大在外");

// 情况B：大的次数在内层
testLoops(small, big, "大在内");