let var_name = new String(string);

let uname = new String("Hello JavaTpoint");
console.log("Message: " + uname);
console.log("Length: "+uname.length);

Message: Hello JavaTpoint
Length: 16

var studentName: String = 'Peter';

var studentName: String = "Peter";

let empName:string = "Rohit Sharma"; 
let compName:string = "JavaTpoint"; 
// Pre-ES6
let empDetail1: string = empName + " works in the " + compName + " company."; 
// Post-ES6
let empDetail2: string = `{empName} works in the{compName} company.`; 
console.log("Before ES6: " +empDetail1);
console.log("After ES6: " +empDetail2);

Before ES6: Rohit Sharma works in the JavaTpoint company.
After ES6: Rohit Sharma works in the JavaTpoint company.

let multi = 'hello ' +
    'world ' +
    'my ' +
    'name ' +
    'is ' +
    'Rohit';

let multi = ' hello\n ' +
    'JavaTpoint\n ' +
    'my\n ' +
    'name\n ' +
    'is\n ' +
    'Rohit Sharma';
console.log(multi);

hello
JavaTpoint
my
name
is
Rohit Sharma

Type variableName = "value1" | "value2" | "value3"; // 直到 N 个值

type Pet = 'cat' | 'dog' | 'Rabbit';
let pet: Pet;
if(pet = 'cat'){
    console.log("Correct");
};
if(pet = 'Deer')
{
    console.log("compilation error");
};

Correct
compilation error

type FruitsName = "Apple" | "Mango" | "Orange";
function showFruitName(fruitsName: FruitsName): void {
    console.log(fruitsName);
}
showFruitName('Mango');   //OK - Print 'Mango'
//Compile Time Error
showFruitName('Banana');

Mango
Banana

//String Initialization
let str1: string = 'Hello';
let str2: string = 'JavaTpoint';
//String Concatenation
console.log("Combined Result: " +str1.concat(str2));
//String charAt
console.log("Character At 4: " +str2.charAt(4));
//String indexOf
console.log("Index of T: " +str2.indexOf('T'));
//String replace
console.log("After Replacement: " +str1.replace('Hello', 'Welcome to'));
//String uppercase
console.log("UpperCase: " +str2.toUpperCase());

Combined Result: HelloJavaTpoint
Character At 4: T
Index of T: 4
After Replacement: Welcome to
UpperCase: JAVATPOINT