1// 3 xil tirnoq
2const a = "ikki qo'shtirnoq";
3const b = 'bitta tirnoq';
4const c = `backtick — template literals`;
5
6// Template literals — eng foydali
7const ism = "Ali";
8const salom = `Salom, ${ism}!`;    // "Salom, Ali!"
9
10// Ko'p qatorli matn
11const sher = `Birinchi qator
12Ikkinchi qator
13Uchinchi qator`;
14
15// Maxsus belgilar
16const tirnoqli = "U: \"Salom\" dedi";   // U: "Salom" dedi
17const yangiQator = "Birinchi\nIkkinchi";  // \n — yangi qator
18const tab = "Ism:\tAli";                   // \t — tabulyatsiya

1const matn = "Salom";
2
3console.log(matn.length);  // 5
4
5// Indeks bilan
6console.log(matn[0]);      // "S"
7console.log(matn[1]);      // "a"
8console.log(matn[4]);      // "m"
9console.log(matn[10]);     // undefined
10
11// Oxirgi belgi
12console.log(matn[matn.length - 1]);  // "m"
13
14// charAt — alternativ
15matn.charAt(0)             // "S"

1const matn = "JavaScript juda qiziqarli til";
2
3// indexOf — topgan birinchi o'rin (yo'q bo'lsa -1)
4matn.indexOf("juda")       // 11
5matn.indexOf("Java")       // 0
6matn.indexOf("Python")     // -1
7
8// lastIndexOf — oxiridan qidiradi
9"banana".lastIndexOf("a")  // 5
10
11// includes — bor/yo'qligini tekshiradi (true/false)
12matn.includes("qiziq")     // true
13matn.includes("zerikarli") // false
14
15// startsWith va endsWith
16"index.html".startsWith("index") // true
17"index.html".endsWith(".html")   // true

1const matn = "JavaScript";
2
3// slice(boshlanish, tugash) — oxiri kirmaydi
4matn.slice(0, 4)      // "Java"
5matn.slice(4)         // "Script"  (oxirigacha)
6matn.slice(-6)        // "Script"  (manfiy — oxiridan)
7matn.slice(-6, -2)    // "Scri"
8
9// substring — slice'ga o'xshash, lekin manfiy ishlamaydi
10matn.substring(0, 4)  // "Java"
11
12// substr (eski, ishlatmang)

1const matn = "Salom, dunyo!";
2
3// Registr
4matn.toUpperCase()       // "SALOM, DUNYO!"
5matn.toLowerCase()       // "salom, dunyo!"
6
7// Almashtirish
8matn.replace("dunyo", "Ali")  // "Salom, Ali!"
9
10// replaceAll — hammasini
11"a-b-c".replaceAll("-", "_")  // "a_b_c"
12
13// Bo'shliqlarni olib tashlash
14"  salom  ".trim()       // "salom"
15"  salom  ".trimStart()  // "salom  "
16"  salom  ".trimEnd()    // "  salom"
17
18// Takrorlash
19"ha".repeat(3)           // "hahaha"
20
21// To'ldirish (padding)
22"5".padStart(3, "0")     // "005"
23"5".padEnd(3, "0")       // "500"

1// split — matnni massivga
2"olma,anor,banan".split(",")    // ["olma", "anor", "banan"]
3"Salom dunyo".split(" ")        // ["Salom", "dunyo"]
4"abc".split("")                 // ["a", "b", "c"]
5
6// join — massivni matnga
7["olma", "anor"].join(", ")     // "olma, anor"
8["2025", "10", "15"].join("-")  // "2025-10-15"
9
10// Foydali qo'llanish — matnni teskariga
11"salom".split("").reverse().join("")  // "molas"