JavaScript for Developers 29 - The Secret behind JavaScript Arrays

In this video, you'll learn about the secret behind JavaScript arrays. And what you learn may surprise you. Just don't tell anyone!

[heyman]

wow, the first js guide that was not a waste of time! great job

[neganega]

I did the js basics for 3 months now and moving on to this one is best decision … very deep yet very well explained

[jeyzzz]

thank you for this short array refresher tutorial. big help!

[mraghul]

Another interesting thing to note here is
1. try delete myArray.length - this wont delete the length property but returns you false.
2. try changing the length value, myArray.length = 5, this will work.
3. try changing the length value to something other than a number myArray.length = "foo", this will fail with message "Invalid array length"

It will be glad to understand what happens here.

[alialrahem]

The good thing about your videos is short And easy to understand not long and boring that difficult to understand thank you to simplify the information

[rashmigandecha]

Thank you so much for superb tutorials, u make everything so easy to understand

[joey]

Really in depth video. Thank you for making

[sbollap]

thank you. very good explanation of showing array is an object

[sparkman]

If the numeric index converts to a string, then is it faster to just use a string?

[rushendrarushi]

wow thank you so much i didn't know that array.length actually counts index..!!

[syedaqib]

8:05 'foo' = 'ABC' is just a property element is not added to array hence the size of the array is same.

[keeranmnc]

Is the type coercion not converting your string "0" to a number 0 when you reference the property/array-index? Since when you print out the array/object using console.log, it prints the property/indexes as numbers.

[Bhanwar-Rathore]

Hello Kaushik, Thanks for delivering such useful content. Many people are getting benefited from your kind efforts. I have one doubt regarding the array insertion:
I want to add an element into an array with an index value but do not want to remove the existing element from that index.
What I am doing here :
var techSkills = ["Java", "React", "JavaScript"];
techSkills.splice("2", 0, "Hibernate");
console.log(techSkills); // output ["Java", "React", "Hibernate", "JavaScript"];
techSkills.splice("2A", 0, "AWS");
console.log(techSkills); // output ["AWS", "Java", "React", "Hibernate", "JavaScript"];

My question is how come it's inserting value at the 0th index. How come the string index value is converting to zero.
Thanks.

[nuruthin]

Thank you for your video. How 'delete myArray[0]' works in the above example? i got ' [undefined × 1, "world", "JS", "foo"] ' when I tried to delete element at 0 index

[dvrreddy]

Sir as you said in the array [4] the number 4 will be converted into string and i have a doubt that we can acces the properties of array using dot notation so once the number is converted into string why can't we access that using the dot notation.

[princechhabra]

If array is an object then do we have an array that has a value which is another array like we have in case of objects?

[TT-udgf]

Do all items in an array have to be the same type?

[richardwang]

It looks that the design of the language is not consistent since the length of an array depends on a number property.

[JoseLuisRomeroFiruzzZ]

"More I know, more I like my old dog (Java)"
Great videos but this language seems so weak, I hope it gets better in next videos.. or century