Say I have two arrays, one of objects, one simple:
var objArray = [{id:1,name:'fred'},{id:2,name:'john'},{id:3,name:'jane'},{id:4,name:'pete'}]
var simpleArray = [1,3]
I want to return a new array with just the items from objArray where the id property value (1,2,3 etc) does not match an item in the simpleArray.
I should have returned:
result = [{id:2,name:'john'},{id:4,name:'pete'}]
I've tried various combinations of $.grep, .filter and $.inArray but struggling with this.
You could try this one:
var results = [];
objArray.filter(function(item){
if(simpleArray.indexOf(item.id)>-1)
results.push(item);
})
Please try the following snippet:
function Customer(id, name){
this.id=id;
this.name=name;
};
this.Customer.prototype.toString = function(){
return "[id: "+this.id+" name: "+this.name+"]";
}
var objArray = [ new Customer(1,'fred'), new Customer(2,'john'), new Customer(3,'jane'), new Customer(4,'pete')];
var simpleArray = [1,3];
var results = [];
objArray.filter(function(item){
if(simpleArray.indexOf(item.id)>-1)
results.push(item);
});
document.write(results)
.filter() just treats the return value as a boolean, so you could just return the result of the .indexOf() test.
@Christos' answer is good for many cases; however, if the simple array gets very large then the performance of that solution will degrade considerably (because it is doing a linear search instead of a constant-time lookup). Here is a solution that will perform well even when the simple array is very large.
function filterByMissingProp(objects, values, propertyName) {
var lookupTable = values.reduce(function(memo, value) {
memo[value] = true;
return memo;
}, {});
return objects.filter(function(object) {
return !(object[propertyName] in lookupTable);
});
}
var result = filterByMissingProp(objArray, simpleArray, 'id');
result; // => [ {id:2, name:"john"}, {id:4, name:"pete"} ]
