Question

I’m trying to use basic operators to create my own custom array in JavaScript, I guess.

This book I’m reading, “Eloquent JavaScript”, has an exercise in Chapter 1 that asks me to make a pyramid using the “print” function. There’s no print function in any of my interpreters, and it doesn’t say how to make a print function. So, I don’t have a print function, and I’m using alerts.

Here’s the code.

var line = "";
var counter = 0;
while (counter < 10) {
  line = line + "#";
  print(line);
  counter = counter + 1;
}

So, I was trying to use alerts, instead:

var line = "";
var counter = 0;
while (counter < 10) {
  line = line + "#";
  alert(line);
  counter = counter + 1;
}

But the alert isn’t a triangle. It’s a bunch of boxes where the number of pound signs grows each time.

I want to create a string concatenation and then print out the entire result.

This is what I came up with:

string = "";
counter = 0;
signs = "#";
while (counter < 10){
  string = string + signs + "\n";
  signs = signs + "#";
  counter = counter + 1;
}
alert(string);

So, I am just wondering, is there a better way to create arrays without knowing how to create array variable?

Answer 1

The newline character is “\n” not “/n”. (The “escape” character in general is backslash not forward slash.)

Also, you have a typo that you said sings = ... instead of signs = ...

EDIT: OK, so you’ve updated your question to correct both of those problems. Regarding your new question:

So, I am just wondering, is there a better way to create arrays
without knowing how to create array variable?

It sounds like you don’t really understand what an array variable is: an array is a data structure that allows you to store data items that are selected by indices. Why do you think you need an array for this “pyramid” functionality?

As an aside, your code could be improved using += and ++:

• a = a + b; can be abbreviated as a += b;
• a = a + 1; can be abbreviated as a++;