ES6

TextUnicode.js

//The codePointAt() Method
let text = "𠮷";
console.log(text.length);
console.log(/^.$/.test(text));
console.log(text.charAt(0));
console.log(text.charAt(1));
console.log(text.charCodeAt(0));
console.log(text.charCodeAt(1));

let text = "𠮷a";
console.log(text.charCodeAt(0));
console.log(text.charCodeAt(1));
console.log(text.charCodeAt(2));
console.log(text.codePointAt(0));
console.log(text.codePointAt(1));
console.log(text.codePointAt(2));

function is32Bit(c) {
    return c.codePointAt(0) > 0xFFFF;
}
console.log(is32Bit("𠮷")); // true 
console.log(is32Bit("a")); // false

//The String.fromCodePoint() Method
console.log(String.fromCodePoint(134071)); // "𠮷"

//The u Flag in Action
let text = "𠮷";
console.log(text.length);
console.log(/^.$/.test(text));
console.log(/^.$/u.test(text));

//Counting Code Points
function codePointLength(text) {
    let result = text.match(/[\s\S]/gu);
    return result ? result.length : 0;
}
console.log(codePointLength("abc"));    // 3
console.log(codePointLength("𠮷bc")); // 3

//Methods for Identifying Substrings
let msg = "Hello world!";
console.log(msg.startsWith("Hello"));
console.log(msg.endsWith("!"));
console.log(msg.includes("o"));
console.log(msg.startsWith("o"));
console.log(msg.endsWith("world!"));
console.log(msg.includes("x"));
console.log(msg.startsWith("o", 4));
console.log(msg.endsWith("o", 8));
console.log(msg.includes("o", 8));