I want to compare a range of numbers against a single number, basically like this in simple terms:

if X through Y equals Z, then do {}

What would be the proper way to do something like that in Javascript?

CLARIFICATION

I want to check if any number between X and Y is equal to Z

I want to compare a range of numbers against a single number, basically like this in simple terms:

if X through Y equals Z, then do {}

What would be the proper way to do something like that in Javascript?

CLARIFICATION

I want to check if any number between X and Y is equal to Z

• javascript

• 1 A range implies a loop. Show us the loop. – Jon Commented Jan 20, 2012 at 16:29
• 1 So you're checking that X through Y are the same number as Z? So X and Y are indices of an array, or something? – user1106925 Commented Jan 20, 2012 at 16:30
• I don't have a loop. This is being used for collision detection of 2 boxes. – rshea0 Commented Jan 20, 2012 at 16:30
• You want to compare every number in the range against z? – Tristian Commented Jan 20, 2012 at 16:30
• what does equals mean? x <= z <= y? – hvgotcodes Commented Jan 20, 2012 at 16:30

6 Answers 6

A range doesn't equal a number, do you mean that the number falls within the range?

if (1 <= Z && Z <= 25 ) {
    foo();
}

If you want to determine if Z is in the range [X, Y], then you can do:

if (X < Z && Z < Y) {
    // do stuff.
}

Otherwise, a range can't equal a number.

var arr = [...];

var compareRange = function(arr, x, y, z){

  for(var i=x; i<=y; i++){
    if(arr[i] != z){
      return false;
    }
  }

  return true;
};

To check if elements 1 through 3 are all 1:

var arr = [0, 1, 1, 1, 2];
var allOne = arr.slice(1, 4).filter(
    function(val) { return val !== 1; }).length === 0;

EDIT

Even better, thanks to @am not i am

var arr = [0, 1, 1, 1, 2];
var allOne = arr.slice(1, 4).every(function (val) { return val === 1; });

First the range function:

function range(a,b){
    var r = [a];
    for(var i=a;i<=b;i++){
         r.push(i);
    }
    return r;
}

Now use the function and make the comparison:

var a = range(1,6); // Range
var z = 7;
if(a.indexOf(z) > -1){
    // Collision !!!
}else{
   // No collision, I suppose...
}

I am not sure I have completely understood your question. I made a function that compares a number n to a range of numbers between min and max. This function returns an integer r from 1 to 5

• n is less than min, r = 1
• n is equal to min, r = 2
• n is between min and max, r = 3
• n is equal to max, r = 4
• n is greater than max, r = 5

function compareToRange(n,min,max){
var r=((n<min)*1+(n==min)*2+((n>min)&&(n<max))*3+(n==max)*4+(n>max)*5);
}