Javascriptda arraylarning izlash metodlari.!
Array indexOf()
Array lastIndexOf()
Array includes()
Array find()
Array findIndex()
Array findLast()
Array findLastIndex()
1. indexOf()
Ushbu metod massiv elementi joylashgan indeks raqamni qaytaradi.
sintaksis: arrayName.indexOf(item,start);
buyerda item-indeks raqami izlanayotgan element, start-indeks raqami izlanayotgan element qayerdan boshlab izlanishi va startga qiymat berish ihtiyoriy. Element bir necha marotaba takrorlangan bo'lsa birinchi topilgan elementni qaytaradi, agar element topilmasa -1 qaytaradi. Ushbu metod elementlarni chapdan o'ngga qarab izlaydi.!
let fruits = ['lemon','mango','nut','peach','strawberry','nut','apelsin'];
console.log(fruits);
//natija - ['lemon','mango','nut','apelsin','peach','strawberry']
let fruits_indexOf1 = fruits.indexOf('nut');
console.log(fruits_indexOf1);
//natija - 2
let fruits_indexOf2 = fruits.indexOf('nut')+1;
console.log(fruits_indexOf2);
//natija - 3
let fruits_indexOf3 = fruits.indexOf('nut')-4;
console.log(fruits_indexOf3);
//natija - -2
let fruits_indexOf4 = fruits.indexOf('nut',4);
console.log(fruits_indexOf4);
//natija - 5
let fruits_indexOf5 = fruits.indexOf('nut',6);
console.log(fruits_indexOf5);
//natija - -1
2. lastIndexOf()
Ushbu metod elementlarni o'ng tarafdan chap tarafga qarab izlaydi va 1-topilgan elementni qaytaradi, sintaksisti indexOf bilan birxil.!
let fruits = ['lemon','mango','nut','peach','strawberry','nut','apelsin'];
console.log(fruits);
//natija - ['lemon','mango','nut','apelsin','peach','strawberry']
let fruits_lastIndexOf1 = fruits.lastIndexOf('nut');
console.log(fruits_lastIndexOf1);
//natija - 5
let fruits_lastIndexOf2 = fruits.lastIndexOf('nut',3);
console.log(fruits_lastIndexOf2);
//natija - 2
3. includes()
Ushbu metod massiv ichidan biror-bir element bor yoki yo'qligini bilish uchun foydalaniladi, agar element bor bo'lsa true bo'lmasa false qiymat qaytaradi.!
sintsksis: `arrayName.includes(item,start);`
item-mos element, start-izlash qayerdan boshlanishi kerakligi. includes() ECMAScript 2016 da kiritilgan.!
let fruits = ['lemon','mango','nut','peach','strawberry','nut','apelsin'];
console.log(fruits);
//natija - ['lemon','mango','nut','apelsin','peach','strawberry']
let fruits_includes1 = fruits.includes('lemon');
console.log(fruits_includes1);
//natija - trtue
let fruits_includes2 = fruits.includes('lemon',3);
console.log(fruits_includes2);
//natija - false
let fruits_includes3 = fruits.includes();
console.log(fruits_includes3);
//natija - false
4. find()
5. findIndex()
6. findLast()
7. findLastIndex()
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