LukevdPalen
11/19/2014 - 1:19 PM

## Number range

Number range

``````/**
* Behaves just like the python range() built-in function.
* Arguments:   [start,] stop[, step]
*
* @start   Number  start value
* @stop    Number  stop value (excluded from result)
* @step    Number  skip values by this step size
*
* Number.range() -> error: needs more arguments
* Number.range(4) -> [0, 1, 2, 3]
* Number.range(0) -> []
* Number.range(0, 4) -> [0, 1, 2, 3]
* Number.range(0, 4, 1) -> [0, 1, 2, 3]
* Number.range(0, 4, -1) -> []
* Number.range(4, 0, -1) -> [4, 3, 2, 1]
* Number.range(0, 4, 5) -> [0]
* Number.range(5, 0, 5) -> []
*   Number.range(5, 4, 1) -> []
* Number.range(0, 1, 0) -> error: step cannot be zero
* Number.range(0.2, 4.0) -> [0, 1, 2, 3]
*/
Number.range = function() {
var start, end, step;
var array = [];

switch(arguments.length){
case 0:
throw new Error('range() expected at least 1 argument, got 0 - must be specified as [start,] stop[, step]');
return array;
case 1:
start = 0;
end = Math.floor(arguments[0]) - 1;
step = 1;
break;
case 2:
case 3:
default:
start = Math.floor(arguments[0]);
end = Math.floor(arguments[1]) - 1;
var s = arguments[2];
if (typeof s === 'undefined'){
s = 1;
}
step = Math.floor(s) || (function(){ throw new Error('range() step argument must not be zero'); })();
break;
}

if (step > 0){
for (var i = start; i <= end; i += step){
array.push(i);
}
} else if (step < 0) {
step = -step;
if (start > end){
for (var i = start; i > end + 1; i -= step){
array.push(i);
}
}
}
return array;
}``````