Exclude some properties in comparison using isEqual() of lodash

Question

I am using _.isEqual that compares 2 array of objects (ex:10 properties each object), and it is working fine.

Now there are 2 properties (creation and deletion) that i need not to be a part of comparison.

Example:

var obj1 = {name: "James", age: 17, creation: "13-02-2016", deletion: "13-04-2016"} var obj2 = {name: "Maria", age: 17, creation: "13-02-2016", deletion: "13-04-2016"}  // lodash method... _.isEqual(firstArray, secondArray) 

Answer 1

You can use omit() to remove specific properties in an object.

var result = _.isEqual(   _.omit(obj1, ['creation', 'deletion']),   _.omit(obj2, ['creation', 'deletion']) ); 

var obj1 = {    name: "James",    age: 17,    creation: "13-02-2016",    deletion: "13-04-2016"  };    var obj2 = {    name: "Maria",    age: 17,    creation: "13-02-2016",    deletion: "13-04-2016"  };    var result = _.isEqual(    _.omit(obj1, ['creation', 'deletion']),    _.omit(obj2, ['creation', 'deletion'])  );    console.log(result);

<script src="https://cdn.jsdelivr.net/lodash/4.13.1/lodash.min.js"></script>

Answer 2

@ryeballar's answer is not great for large objects because you are creating a deep copy of each object every time you do the comparison.

It's better to use isEqualWith. For example, to ignore differences in the "creation" and "deletion" properties:

var result = _.isEqualWith(obj1, obj2, (value1, value2, key) => {     return key === "creation" || key === "deletion" ? true : undefined; }); 

EDIT (important caveat pointed out in the comments): if objects have different numbers of keys, then isEqualWith considers them to be different, regadless of what your customizer does. Therefore do not use this approach if you want to ignore an optional property. Instead, consider using _.isMatch(), _.isMatchWith(), or @ryeballar's _.omit() approach.

Note that if you're writing for ES5 and earlier, you'll have to replace the arrow syntax (() => {) with function syntax (function() {)