/pattern/flags
.test(str) — return true/false.match(regex) — return matches.replace(regex, replacement)g — global (semua match)i — case insensitive\d digit, \w word, \s whitespace+ satu/lebih, * nol/lebih, ? opsional[abc] karakter class, ^ awal, $ akhirconst email = /^[\w.-]+@[\w.-]+\.\w{2,}$/;
const phone = /^08\d{8,12}$/;
const o = document.getElementById('output');
o.innerHTML =
'// Test
'+
'email: test@mail.com → '+email.test("test@mail.com")+'
'+
'email: invalid → '+email.test("invalid")+'
'+
'phone: 081234567890 → '+phone.test("081234567890")+'
'+
'phone: 12345 → '+phone.test("12345")+'
'+
'// Match
'+
'"I have 3 cats and 2 dogs".match(/\\d+/g)
→ '+JSON.stringify("I have 3 cats and 2 dogs".match(/\d+/g))+'
'+
'// Replace
'+
'"Hello World".replace(/o/g, "0")
→ '+"Hello World".replace(/o/g, "0");