javascript - jQuery does not get correctly values of all checked checkbox -

i have list of checkboxes checked follow:

<input type="checkbox" name="capacity" value="16" checked> 16 <br> <input type="checkbox" name="capacity" value="32" checked> 32 <br> <input type="checkbox" name="capacity" value="64" checked> 64 <br> <input type="checkbox" name="capacity" value="128" checked> 128 <br> 

each time checkbox checked or unchecked, want update capacity list again, therefore, use (with little bit of repeating code):

$('input[name="capacity"]').change(function() {    var capacity = $('input[name="capacity"]:checked').map(function() {         return this.value;     }).get();    console.log(capacity); }) 

however, capacity still contains value of last unchecked checkbox. when unchecked 128 -> capacity = ["16","32","64","128"]. then, unchecked 32 -> capacity =["16","32","64"]

i don't understand strange behavior or doing wrong?