Does JavaScript have a range() equivalent?

Answer 1

The standard Javascript doesn't have a built-in function to generate ranges. Several javascript frameworks add support for such features, including Prototype.js.

If you'd like to double-check, the definitive resource is the ECMA-262 Standard.

Answer 2

This one works for numbers...

function numberRange(lower, upper) {

    var numbers = [],
        modify = 1;

    if (lower > upper) {
        modify = -1;
    }

  upper += modify;
  while (lower != upper) {

      numbers.push(lower);
      lower += modify;
  }

  return numbers;
}


console.log(numberRange(1, 5)); //  [1, 2, 3, 4, 5]
console.log(numberRange(5, 1)); //  [5, 4, 3, 2, 1]

Answer 3

Array.range= function(a, b, step){
    var A= [];
    if(typeof a== 'number'){
        A[0]= a;
        step= step || 1;
        while(a+step<= b){
            A[A.length]= a+= step;
        }
    }
    else{
        var s= 'abcdefghijklmnopqrstuvwxyz';
        if(a=== a.toUpperCase()){
            b=b.toUpperCase();
            s= s.toUpperCase();
        }
        s= s.substring(s.indexOf(a), s.indexOf(b)+ 1);
        A= s.split('');        
    }
    return A;
}


    Array.range(0,10);
    // [0,1,2,3,4,5,6,7,8,9,10]

    Array.range(-100,100,20);
    // [-100,-80,-60,-40,-20,0,20,40,60,80,100]

    Array.range('A','F');
    // ['A','B','C','D','E','F')

    Array.range('m','r');
    // ['m','n','o','p','q','r']