type script

ref

• https://code.visualstudio.com/docs/editor/debugging#_debug-actions
• https://www.youtube.com/watch?v=d56mG7DezGs

  env

• tsc -v:type script compiler
• npm install -g typescript
• let age: number=10
• annotatage age with number
• on doing tsc ts1.ts a ts1.js is made
• for let age:number=2=>var age = 2;
• usually tsc convets to old js,to use new js change the targe in below file
• tsc --init=>creates tsconfig.json
• we have contorl over source files and where generated destination files will be by changing tsconfig.json
• like this if we have a folder then to run ts files we can just tsc which will compile all ts files
• in vs code we have in debug panel ,a create launch.json file,it tells vs code how to debug this app
• declared uninilized variables are of type any
• with this we can do

  let a;
  a=10
  a="abcd"
  function t(a){//implicity any gives err
    console.log(a)
  }
  let aray1:number[]=[1,2]
  

• in some cases implicit any returns err,to turn it off change change tsconfig.ts
• tuples type in ts:

  let student:[number,string]=[191034,"mounika"]
  

• enum Color={“red”,”blue”,”green”};let x:C0lor=Color.red
• for functions

  function voteEligibility(age:number):boolean{
    ...
    return false    
  }