for loop versus foreach

Question

I am fairly new at programming still, and I'm having a hard time been wishing for different between for/foreach. In a more technical exclamation, the for each loop counts how many times it is needed-unlike the code below.

Let's say I have been a sample of a for loop like this:

var i = result = 0;
for (var i = 2; i < process.argv.length; i++) {
    result = result + Number(process.argv[i]);
}

console.log(result);

How would this code change if it were a foreach statement? Is the explanation right? Or is there more to it?

Thank you in Advance.

Answer 1

A foreach loop goes through all the elements in an array and gives them to you one by one without having to do any messing about with an iteration variable with 'i'. For example, you could do this:

var result = 0;
process.argv.forEach(function(element){
   result = result + element;
});

There is a difference between your code and this code: your code skipped the first two elements because 'i' started at 2. This is harder to do in a foreach loop, and if you need that, you should stick to a for loop.

The foreach loop sets up the counters for you. Convenient, but less flexible. It always starts at the first element and ends at the last one. One cool thing to notice is that we also don't have to do anything like '[i]'. The element in the array is pulled out and passed to our function.

In conclusion, a foreach loop is simply a simplified for loop for cases when you need to look at every element in an array.

I personally think the foreach loop in node.js is ugly, since it isn't really a statement, just a function attached to arrays. I much prefer how they look in something like php where they are a part of the language:

$result = 0;
foreach ($process as $element) {
    $result = $result + $element;
}

But that is just personal taste.