Java Script uchun qo’llanma Samarqand Davlat universiteti talabasi Ibrohimov Ismoiljon tomonidan tayyorlandi. Kamchiliklar uchun uzr…!

Eslatma

Usul replace()chaqirilgan satrni o'zgartirmaydi.
Usul replace()yangi qatorni qaytaradi.
Usul faqat birinchi moslikni replace()almashtiradi
let text = "Please visit Microsoft and Microsoft!";
let newText = text.replace("Microsoft", "W3Schools");
// Please visit Microsoft and Microsoft!

2021 yilda JavaScript string usulini taqdim etdi replaceAll():

Misol

let text = "I love cats. Cats are very easy to love. Cats are very popular."
text = text.replaceAll("Cats","Dogs");
text = text.replaceAll("cats","dogs");
// I love dogs. Dogs are very easy to love. Dogs are very popular.

Satr quyidagi bilan katta harfga aylantiriladi toUpperCase():

Satr quyidagi bilan kichik harfga aylantiriladi toLowerCase():
concat() ikki yoki undan ortiq qatorlarni birlashtiradi:

text = "Hello" + " " + "World!";

text = "Hello".concat(" ", "World!");

ECMAScript 2019 JavaScript-ga String trimStart() usulini qo'shdi .

Usul trimStart() trim() kabi ishlaydi , lekin bo'shliqni faqat satr boshidan olib tashlaydi.
Usul trimEnd() trim() kabi ishlaydi , lekin bo'shliqni faqat satr oxiridan olib tashlaydi.

ECMAScript 2017 ikkita String usulini qo'shdi: padStart() va padEnd()satr boshida va oxirida to'ldirishni qo'llab-quvvatlash uchun.

Usul padStart()satrni boshqa satr bilan to'ldiradi:

Misol

let text = "5";
let padded = text.padStart(4,"x"); // xxx5

Misol
let text = "5";

let padded = text.padStart(4,"0"); // 0005

let numb = 5;

let text = numb.toString();
let padded = text.padStart(4,"0"); // 0005

Usul padEnd()satrni boshqa satr bilan to'ldiradi:

Misol

let text = "5";
let padded = text.padEnd(4,"x"); // 5xxx

Satr belgilarini ajratib olishning 3 ta usuli mavjud:

• 
  charAt(position)
  
• 
  charCodeAt(position)
  
• 
  Mulkga kirish [ ]
  

Usul charAt()satrdagi belgilangan indeks (pozitsiya)dagi belgini qaytaradi:

Misol

let text = "HELLO WORLD";
let char = text.charAt(0); // H
Usul charCodeAt()satrda belgilangan indeksdagi belgining unikodini qaytaradi:
Usul UTF-16 kodini qaytaradi (0 dan 65535 gacha bo'lgan butun son).
Misol
let text = "HELLO WORLD";
let char = text.charCodeAt(0); // 72

ECMAScript 5 (2009) satrlarda [ ] mulkiga kirish imkonini beradi:

Misol

let text = "HELLO WORLD";
let char = text[0]; // H

Agar siz satr bilan massiv sifatida ishlamoqchi bo'lsangiz, uni massivga aylantirishingiz mumkin.

Satrni quyidagi usul bilan massivga aylantirish mumkin split():

Misol