Typescript type alias

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1. What is a type alias ?
A type alias is a new name for a type , But they all represent the same type
for example : Your real name is Zhang San , Your nickname is Xiao San , Xiao San is the alias of Zhang San , Both Zhang San and Xiao San mean the same person
1. to string Type has an alias called MyString, So in the future, whether it is MyString still string All means string

type MyString = string;
let value:MyString;
value = 'abc';
value = 123;
value = false;

2. Type aliases can also use generics

type MyType<T> = {
    x:T, y:T};
let value:MyType<number>;
value = {
    x:123, y:456};// because T yes number, It can only be number
value = {
    x:'123', y:456};// Report errors 
value = {
    x:false, y:456};// Report errors 

3. Use yourself in a property of a type alias type

type MyType = {
    
    name:string,
    //  It is generally used to define some tree structures or nested structures 
    children?:MyType
}
let value:MyType = {
    
    name:'one',
    children:{
    
        name:'one',
        children:{
    
            name:'one',
        }
    }
}

4. Interface and type aliases are compatible

type MyType = {
    
    name:string
}
interface MyInterface {
    
    name:string
}
let value1:MyType = {
    name:'lnj'};
let value2:MyInterface = {
    name:'zs'};
value1 = value2;
value2 = value1;