javascript - Splicing Array Based on For Loop Iteration -

i trying take array ('selectedworkshops'), , move objects in 'registeredworkshops'. then, want remove objects both 'selectedworkshops' , array called 'workshops'.

see codepen here: http://codepen.io/truescript/pen/wbvqnn

arrays:

var workshops = [   {     name: 'apples',     workshopid: '19'   },   {     name: 'oranges',     workshopid: '3b'   },   {     name: 'pears',     workshopid: 'x6'   },   {     name: 'pineapples',     workshopid: '55'   },   {     name: 'watermelons',     workshopid: '8v'   } ];  var selectedworkshops = [   {     name: 'oranges',     workshopid: '3b'   },   {     name: 'watermelons',     workshopid: '8v'   },   {     name: 'pears',     workshopid: 'x6'   } ];  var registeredworkshops = []; 

function supposed move workshops 'registeredworkshops' , remove them 'selectedworkshops' , 'workshops':

flipworkshops = function(){     var numberofworkshops = selectedworkshops.length;     var x = 1;     for(var = 0; < numberofworkshops; i++ ){         registeredworkshops.push(selectedworkshops[i]);         for(var j = 0, arraylength = workshops.length; j < arraylength; j++) {             var selectedworkshop = selectedworkshops[i];             var originalworkshop = workshops[j];             if(selectedworkshop == originalworkshop){                 var matchingworkshop = j;                 workshops = workshops.splice(j, 1);                 selectedworkshops = selectedworkshops.splice(i, 1);             }         }     } }; flipworkshops(); 

why aren't objects being spliced out of 'workshop' , 'selectedworkshops' arrays should be? doing wrong?

"the splice() method adds/removes items to/from array, , returns removed item(s)." http://w3schools.com/jsref/jsref_splice.asp so, basically, you're reducing workshops single object, removed array element.

instead, change:

workshops = workshops.splice(j, 1); selectedworkshops = selectedworkshops.splice(i, 1); 

...to:

workshops.splice(j, 1); selectedworkshops.splice(i, 1); 

jsfiddle

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maybe want:

var registeredworkshops = []; var flipworkshops = function(){     var numberofworkshops = selectedworkshops.length;     var x = 1;     for(var = numberofworkshops - 1; >= 0; i-- ){         registeredworkshops.push(selectedworkshops[i]);         var selectedworkshop = selectedworkshops[i];         for(var j = workshops.length - 1; j >= 0; j--) {             var originalworkshop = workshops[j];             if(selectedworkshop.name == originalworkshop.name &&               selectedworkshop.workshopid == originalworkshop.workshopid){                 var matchingworkshop = j;                 workshops.splice(j, 1);                 selectedworkshops.splice(i, 1);             }         }     } }; flipworkshops(); 

fixed splice, reversed loop, suggested jwatts1980, moved selectedworkshop var out of loop, , compared each object item, rather comparing objects, since objects don't compare.

jsfiddle tweaked

jsfiddle object compare example