Typescript compilation generation file comparison

Example 1：

Before compiling TS

let tsnum:number = 8888;
console.log(' This is a ts Precompiled js Code file ,tsnum The value is ：'+tsnum);

The compiled TS（js file ）

var tsnum = 8888;
console.log(' This is a ts Precompiled js Code file ,tsnum The value is ：' + tsnum);

Example 2：

Before compiling TS

//  Use tsc Command compilation produces the same js Code   And run to see the effect 
//  have access to ts-node Package to precompile ts Code   Simplify the compilation process   avoid ts Recompilation caused by code changes 
//  The essence is that script mode replaces manual execution tsc command 
let num:number = 300;
console.log(num)

The compiled TS（js file ）

var num = 300;
console.log(num);