Javascript [ ] concept

Question

Hi Everyone, I need to understand the logic behind console.log([]==[]) ; the console will give the false for above but I do not know whats the logic behind this. Please help me. Thanks in Advance.

Manav Pandya · Answer

Hello As per your sentence , you are comparing array 1 == : It compares types of array that you have use By default array declared is empty , and you are comparing with another empty array That's why it shows false 2 === : It compares both data type and also value to given them So here in your example when im modify like : console.log([] === []); It shows output as : false For example : If you want to get type of anyone you can use console.log( typeof []); Output : object In short you are comparing two object types You can try by implementing simple example : var cars = [ ]; var cars = [ ]; document.write(cars == cars); You will get output like : true I hope it helps Thanks

Prakash Chasiya · Answer

Hello Rakesh; Javascript arrays are objects and we can not simply use the == operator to compare the contents of the objects. It will compare two objects if they are at same instance. Example given below: var a; var b; if (a == b) //true if (null == null) //true if (undefined == undefined) //true You can also compare two objects by converting it to string, but the property for both objects will be the same as given below in example: if(JSON.stringify(["a:a","b:b"])== JSON.stringify(["a:a","b:b"])) //true if(JSON.stringify([])== JSON.stringify([])) //true Hope this is easy to understand. Thanks

Sumit Chaudhary · Answer

var cars = ["Saab", "Volvo", "BMW"]; cars[0]==cars[0]; This is true because there is reference 'cars' but [0]==[0] there is no reference so that condatation could not true

B Patel · Answer

You didin't specified element positon in array. you are comparing empty array thats why it is returning False.

Cynthia Sathuragiri · Answer

Since [] creates a new instance of an array .So you are comparing one array object with the other array object and not with the contents of the array.Thus [] ==[] not equal and produces the result 'false'

Rakesh Singh · Answer

Thank you so much all.

Javascript [ ] concept

Answers (6)