Finding average, minimum, and maximum value in an array.

Hi Mohammed.

Thanks for your help! Are you able to see what I responded to William? That is my follow-up question...

Cheers, Jenn

Thank you, William! Sorry about my formatting; I will fix that for future posts. (I have no idea what I even posted; it was not what the code I have written in my notes; strange). What I initially had was:

var x = [1, 3, 4, 23, 12, 6, 3];
var max = 0;
var min = 0;
var total =0;

for (var i = 0; i < x.length; i++) {
  if (x[i] > max) {
     max = x[i];
   }
  else if (x[i] < min) {
    min = x[i];
  }
  total += x[i];
}

console.log(max);
console.log(min);
console.log(total/x.length);

So, with my above code, I ran into the problem of my min never being less than 0, and my max never greater than 0 if my array was made up of completely negative numbers. I see how you fixed that!

A follow up: I noticed both you and Mohammed removed the if/else statements and instead contained everything in the for statement. I don't believe I've learned this component of coding yet; do you mind expanding why you were able to do:

if (myArray[i] < min) {min = myArray[i];}

without any cod between the () and {}?

Thanks!

Jenn

Hi, Jenn

if (myArray[i] < min) {min = myArray[i];}

// same as
if (myArray[i] < min) {
  min = myArray[i];
}

You can even do it without {} if it's just one line statement

if (myArray[i] < min)
  min = myArray[i];

William Li is right If your if statement only has one line you can omit the curly braces. It also works with for/while loops if you have one statement like :

for(var i = 0; i < 10; i++)
  console.log(i);

Sure

x.splice(x.indexOf(-3), 1);

should get the job done.

I'd like to add that, if you have an array of numbers, and you wanna get rid of all negative numbers, the simplest way is still using for loop to loop over each item in the array, and append it to a new array if it's NOT negative.

If you are just doing so for the purpose of learning javascript, it's fine; but if you're building for a real web app, you generally don't wanna write such tedious JavaScript codes for such simple task, instead you should be using a JavaScript library, such as Underscore.js to do the job.

_.filter([-3, 5, 1, 3, 2, 10, -9], function(number) {return num>=0;});
// => [5, 1, 3, 2, 10]

That's Underscore's way of doing it, very clean and concise.