Error Handling & Important topics in ES6
Error handling
If there are any errors in code because of mistakes. You can handle those errors by using “try.. catch”. Try is executed if there were no errors occur and catch ignored. If an error occur then catch is executed.
Example:
Var declaration and hoisting
Hoisting is a technique where variables and function declarations using var move top of their scope before execution no matter where they actually declared.
Example:
Block-Level Declarations
Block-level declarations mean that declare variables that can not access outside of the given block scope. Block scopes are created:
1. Inside of a block
2. Inside of function
Let Declaration
Let declarations be the same as var declaration. But you can only access it in the current code block. Since let declarations are not lifted up to the top of the enclosing block.
Block Binding in Loops
variable declare using “var” will be accessible after the loop is completed because the var declaration gets hoisted.
Still, variable “i” can access after the loop is completed because of “var”. declaration.
If you declare variable “i” using “let”. You will be inaccessible after the loop is completed.
Function Scope
When variables are declared inside a function. The variables are only accessible inside the function and inaccessible outside of the function.
Functions with Default Parameter
Default function parameters allow initialized default value as a parameter if no value is passed.
The Spread Operator
Spread Operator(…) used to copy an array, inserting element of one array element to another, can pass as function arguments.
Arrow Function
Arrow functions allow an alternative way to write a function in shorter syntax compared to the traditional function expression.
Destructuring
Destructuring assignment allows us to unpack arrays or objects properties into distinct variables.
