“Expert JavaScript ”

1 . Discuss about Error handling

  1. in error handling using Four keyword
  2. try
  3. catch
  4. finally
  5. throw

2. try catch use finally block

  1. There may be no catch section or no finally, so shorter constructor and try..catch are also valid.

3 .Coding Style

  1. Curly Braces
  2. line lentgh
  3. Indents :
  4. semicolon
  5. nesting lavel
  6. function placement
  7. style guide
  8. automated linters

4 .JavaScript comments

5. ES6/ECMAScript


  • Hoisting Bangla meaning Uttolon or Uporer dike tola
Hoisting example image

7. Block-level declaration, Block-Binding

  1. Inside of a function
  2. Inside of a block (indicated by the { and } characters)


  1. it al time can use
  1. if have possibility to change the variable name then use the let l

8 .Function default parameter

default parameter image

9 .Spread Operator

  1. The spread operator allows an expression to be expanded in places where multiple arguments (for function calls) or multiple elements (for array literals) are expected.
Spread operator image

10. Arrow function

arrow function
multiline arrow function



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