How to check if a number is between two values?

Tests whether windowsize is greater than 500 and lesser than 600 meaning that neither values 500 or 600 itself will result in the condition becoming true.

if (windowsize > 500 && windowsize < 600) {
  // ...
}

I had a moment, so, although you've already accepted an answer, I thought I'd contribute the following:

Number.prototype.between = function(a, b) {
  var min = Math.min.apply(Math, [a, b]),
    max = Math.max.apply(Math, [a, b]);
  return this > min && this < max;
};

var windowSize = 550;

console.log(windowSize.between(500, 600));

JS Fiddle demo.

Or, if you'd prefer to have the option to check a number is in the defined range including the end-points:

Number.prototype.between = function(a, b, inclusive) {
  var min = Math.min.apply(Math, [a, b]),
    max = Math.max.apply(Math, [a, b]);
  return inclusive ? this >= min && this <= max : this > min && this < max;
};

var windowSize = 500;

console.log(windowSize.between(500, 603, true));

JS Fiddle demo.

Edited to add a minor amendment to the above, given that – as noted in the comments –

…Function.prototype.apply() is slow! Besides calling it when you have a fixed amount of arguments is pointless…

it was worth removing the use of Function.prototype.apply(), which yields the amended versions of the above methods, firstly without the 'inclusive' option:

Number.prototype.between = function(a, b) {
  var min = Math.min(a, b),
    max = Math.max(a, b);

  return this > min && this < max;
};

var windowSize = 550;

console.log(windowSize.between(500, 600));

JS Fiddle demo.

And with the 'inclusive' option:

Number.prototype.between = function(a, b, inclusive) {
  var min = Math.min(a, b),
    max = Math.max(a, b);

  return inclusive ? this >= min && this <= max : this > min && this < max;
}

var windowSize = 500;

console.log(windowSize.between(500, 603, true));

JS Fiddle demo.

References:

• Function.prototype.apply().
• Math.max().
• Math.min().

I prefer to put the variable on the inside to give an extra hint that the code is validating my variable is between a range values

if (500 < size && size < 600) { doStuff(); }

You can use Multiple clause in if condition instead of writing

if (windowsize > 500-600) {
    // do this
}

because this really makes no sense logically JavaScript will read your if condition like

windowSize > -100 

because it calculates 500-600 to -100

You should use && for strict checking both cases for example which will look like this

if( windowSize > 500 && windowSize < 600 ){

// Then doo something

}

I just implemented this bit of jQuery to show and hide bootstrap modal values. Different fields are displayed based on the value range of a users textbox entry.

$(document).ready(function () {
    jQuery.noConflict();
    var Ammount = document.getElementById('Ammount');

    $("#addtocart").click(function () {

            if ($(Ammount).val() >= 250 && $(Ammount).val() <= 499) {
                {
                    $('#myModal').modal();
                    $("#myModalLabelbronze").show();
                    $("#myModalLabelsilver").hide();
                    $("#myModalLabelgold").hide();
                    $("#myModalPbronze").show();
                    $("#myModalPSilver").hide();
                    $("#myModalPGold").hide();
                }
            }
    });

It's an old question, however might be useful for someone like me.

lodash has _.inRange() function https://lodash.com/docs/4.17.4#inRange

Example:

_.inRange(3, 2, 4);
// => true

Please note that this method utilizes the Lodash utility library, and requires access to an installed version of Lodash.

Here is the shortest method possible:

if (Math.abs(v-550)<50) console.log('short')
if ((v-500)*(v-600)<0) console.log('short')

Parametrized:

if (Math.abs(v-max+v-min)<max+min) console.log('short')
if ((v-min)*(v-max)<0) console.log('short')

You can divide both sides by 2 if you don't understand how the first one works;)