OVMS3/OVMS.V3/components/duktape/examples/guide/prime.js

32 lines
883 B
JavaScript

// prime.js
// Pure ECMAScript version of low level helper
function primeCheckECMAScript(val, limit) {
for (var i = 2; i <= limit; i++) {
if ((val % i) == 0) { return false; }
}
return true;
}
// Select available helper at load time
var primeCheckHelper = (this.primeCheckNative || primeCheckECMAScript);
// Check 'val' for primality
function primeCheck(val) {
if (val == 1 || val == 2) { return true; }
var limit = Math.ceil(Math.sqrt(val));
while (limit * limit < val) { limit += 1; }
return primeCheckHelper(val, limit);
}
// Find primes below one million ending in '9999'.
function primeTest() {
var res = [];
print('Have native helper: ' + (primeCheckHelper !== primeCheckECMAScript));
for (var i = 1; i < 1000000; i++) {
if (primeCheck(i) && (i % 10000) == 9999) { res.push(i); }
}
print(res.join(' '));
}