let textA = 'I like APPles very much';
let textB = 'I like APPles';
let regex = /apples$/i
 
console.log(regex.test(textA)); // false
console.log(regex.test(textB)); // true

let text = 'I like APPles very much';
let regexA = /apples/;
let regexB = /apples/i;

console.log(text.search(regexA)); // -1
console.log(text.search(regexB)); // 7

let text = 'Do you like apples?';
let regex= /apples/;
// Output: apples
console.log(regex.exec(text)[0]);
// Output: Do you like apples?
console.log(regex.exec(text).input);

let text = 'Here are apples and apPleS';
let regex = /apples/gi;
 
// Output: [ "apples", "apPleS" ]
console.log(text.match(regex));

let text = 'This 593 string will be brok294en at places where d1gits are.';
let regex = /\d+/g
 
// Output: [ "This ", " string will be brok", "en at places where d", "gits are." ] 
console.log(text.split(regex))

let regex = /t(e)(st(\d?))/g;
let text = 'test1test2';
let array = [...text.matchAll(regex)];
// Output: ["test1", "e", "st1", "1"]
console.log(array[0]);
// Output: ["test2", "e", "st2", "2"]
console.log(array[1]);

let text = 'Do you like aPPles?';
let regex = /apples/i
 
// Output: Do you like mangoes?
let result = text.replace(regex, 'mangoes');
console.log(result);

/d/s.dotAll;             // => true
/d/g.global;             // => true
/d/ig.flags;             // => "gi"
/d/d.hasIndices;         // => true
/d/i.ignoreCase;         // => true

let s = "Please yes\nmake my day!";

s.match(/yes[^]*day/);
// 返回 'yes\nmake my day'

let regex = /apples/gi;
let text = 'Here are apples and apPleS';

text.replaceAll(regex, "mangoes");
// 返回: Here are mangoes and mangoes