Our Prime Numbers code in Javascript.
Prime Numbers Javascript File:
var start = 1
var end = 99;
var progress = 9;
var do_next_iteration = false;
var prime_numbers = []; // This array variable would hold our prime numbers as they get verified.
/*
* STEP 1:
*/
prime_numbers[0] = 2;
prime_numbers[1] = 3;
prime_numbers[2] = 5;
prime_numbers[3] = 7;
var square_root = 0;
var index = 0; // index into our array
var current = 3; // Points to the current occupied array position.
/*
* STEP 2:
*/
for (; progress < end; progress += 2) {
do_next_iteration = false; // a flag
//STEPS 3, 4:
/*
* Alright, one last check.
* See to it that no prime number less than variable progress is a factor.
*/
square_root = Math.abs(Math.sqrt(progress));
index = 0;
for (; prime_numbers[index] <= square_root; index++) {
if ((progress % prime_numbers[index]) == 0) {
do_next_iteration = true;
break;
}
}
if (do_next_iteration) {
continue;
}
/*
* If 'progress' cleared all those hurdles, then it is definitely a prime number.
* We'll also get our subset of smaller prime numbers from here.
*/
prime_numbers[++current] = progress;
}HTML File:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>Listing Prime Numbers</title>
<script src="PrimeNumbers.js"></script>
</head>
<body>
<h4>
Prime numbers are numbers that can only be divided by themselves and 1
without remainder.<br />Here is a list of them (between 1 and 99 inclusive).
</h4>
<div id="my_primes"></div>
<script>
/*
* The array variable prime_numbers has our prime numbers.
* Use the array method 'join' to display the values.
*/
document.getElementById("my_primes").innerHTML = prime_numbers.join(", ");
</script>
</body>
</html>Try it out!
Elegance (0.0)
