Tag: foreach

What is the difference between .map, .every, and .forEach?

I’ve always wondered what the difference between them were. They all seem to do the same thing… Answer The difference is in the return values. .map() returns a new Array of objects created by taking some action on the original item. .every() returns a boolean – true if every element in this array satisfies the provided testing function. An important

Iterating over result of getElementsByClassName using Array.forEach

foreach getelementsbyclassname javascript

I want to iterate over some DOM elements, I’m doing this: but I get an error: document.getElementsByClassName(“myclass”).forEach is not a function I am using Firefox 3 so I know that both getElementsByClassName and Array.forEach are present. This works fine: Is the result of getElementsByClassName an Array? If not, what is it? Answer No, it’s not an array. As specified in

When iterating over values, why does typeof(value) return “string” when value is a number? JavaScript

foreach javascript typeof

I’m using Google Chrome for this test: Contrary to intuition, the first loop alerts “string” three times, while the second loop alerts “number” three times. I was expecting both loops to alert “number” three times. How is the first loop implemented in JavaScript? In other words, if the for-each is syntactic sugar, what is its equivalent using a standard loop?