Iterate Through an Array with a For Loop

[zilongxuan001]

介绍

JavaScript一个常见的工作就是遍历array的内容，其中一个方法就是用for loop。

方法

var arr = [10,9,8,7,6];
for (var i=0; i < arr.length; i++) {
   console.log(arr[i]);
}

Remember that Arrays have zero-based numbering, which means the last index of the array is length - 1. Our condition for this loop is i < arr.length, which stops when i is at length - 1.

练习

Declare and initialize a variable total to 0. Use a for loop to add the value of each element of the myArr array to total.

代码

// Example
var ourArr = [ 9, 10, 11, 12];
var ourTotal = 0;

for (var i = 0; i < ourArr.length; i++) {
  ourTotal += ourArr[i];
}

// Setup
var myArr = [ 2, 3, 4, 5, 6];

// Only change code below this line
var total = 0;

for (var i = 0; i < myArr.length; i++) {
  total += myArr[i];
}

结果显示

来源

https://www.freecodecamp.org/challenges/iterate-through-an-array-with-a-for-loop