PRIMITIVE VS NON -PRIMITIVE

• PRIMITIVES ARE COPIED BY THEIR VALUE

• REFERENCE(non-primitive) ARE COPIED BY THEIR ADRESS/REFERENCES

• primitive value types => string , number, boolean, undefined, null

• non-primitive(reference type) types => array ,object ,function ==> here all are objects

• what is the difference between them

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Variable name convention Rules :

• The first character must be a letter or an underscore ( - ) or an dollar ( $ ) . You can't use a number as the first character .

• The rest of the variable name can include any letter , any number , or the underscore . Can't use any other characters , including spaces .

• Variable names are case sensitive . No limit to the length of the variable name .

• You can't use one of JavaScript's reserved words as a variable name

• we cant use special character in name

• Datatypes in Javascript

  Six Data Types that are primitives

  • Boolean : typeof instance === " boolean "

  • undefined : typeof instance === " undefined "

  • Number : typeof instance === " number "

  • String : typeof instance === " string "

  • BigInt : typeof instance === " bigint "

  • Symbol : typeof instance === " symbol "