1、使用for循环对数组求和代码: let sum = 0; let numbers = [1, 2, 3]; // 使用for循环求和 for(let i = 0; i < numbers.length; ++i) { sum += numbers[i]; } console.log('sum is ', sum) // sum is 6
2、使用forEach对数组求和代码: let sum = 0; let numbers = [1, 2, 3]; // 使用forEach()函数求和 numbers.forEach(function(number) { sum += number; }); console.log('sum is ', sum) // sum is 6解析: 函数forEach()是数组的内置方法.
3、使用高级函数reduce()对数组求和代码: let numbers = [1, 2, 3]; // 使用reduce()函数求和 let sum = nu罪焐芡拂mbers.reduce((currentSum,currentValue)=>{ currentSum += currentValue; return currentSum; }, 0); console.log('sum is ', sum) // sum is 6解析: let sum = numbers.reduce((currentSum,currentValue)=>{ currentSum += currentValue; return currentSum; }, 0); reduce()函数的初始值为0, currentSum不断累加数组numbers当前的元素, 再将累加的结果传递给下一个元素所在的环境中,再次累加当前的元素,依次类推,最后累加到最后一个元素时,返回最终的结果.
