Types in Javascript

Question 1

What is Static and Dynamically Typed?

Answer 1

Typescript is a statically typed language, which will be compiled into javascript.
Fewer bugs and fails and compile time.

Question 2

Different Types in Javascript?

Answer 2

Numbers : 5
Boolean: true
String: “To be or not to be”
Object : {}
undefined
null
Symbol

Question 3

What is type of?

Answer 3

Type of show the type of the data

Question 4

What is type of null?

Answer 4

Object

Question 5

What is type of array and function?

Answer 5

Object

Question 6

What is difference between undefined and null?

Answer 6

Undefined is absence of the definition.
Null is absence of the value.

Question 7

What are primitive type and non-primitive types?

Answer 7

Primitive types are absolutely which contain the same value
Non-primitive is something like function and array which is a type of object.

Question 8

What is Array.isArray()?

Answer 8

Used to check it has array in js

Question 9

Pass by reference vs pass by value?

Answer 9

Object and array is used as reference.

To copy object or array we can use spread operators. Object.assign({}, obj).

Variables are passed as values.

Question 10

How to copy object and array?

Answer 10

To copy an object or array, we can use spread operators.
JSON stringify to parse.
Object.assign({}, obj).

Question 11

What is type coercion?

Answer 11

Acting as a different variable.

1 == ‘1’ // true
1 === ‘1’ // false

Question 12

Do all languages have type coercion?

Answer 12

Yes, because everything is converting to binary at the end.

Question 13

Is it every-time you are using === instead of == ?

Answer 13

It’s not mandatory but recommended.