JavascriptBlog.

References

Array.copyWithin()

Array.findIndex()

Array.flatMap()

Array.forEach()

Array.includes()

Array.indexOf()

Array.isArray()

Array.lastIndexOf()

Array.reduceRight()

Array.reverse()

Array.toString()

Array.unshift()

Function.toString()

JSON.stringify()

Object.assign()

Object.create()

Object.defineProperties()

Object.defineProperty()

Object.entries()

Object.freeze()

Object.fromEntries()

Object.getOwnPropertyDescriptor()

Object.getOwnPropertyDescriptors()

Object.getOwnPropertyNames()

Object.getOwnPropertySymbols()

Object.getPrototypeOf()

Object.hasOwn()

Object.hasOwnProperty()

Object.isExtensible()

Object.isFrozen()

Object.isPrototypeOf()

Object.isSealed()

Object.preventExtensions()

Object.setPrototypeOf()

Object.toLocaleString()

Object.values()

Promise.allSettled()

Promise.finally()

String.charAt()

String.charCodeAt()

String.concat()

String.endsWith()

String.fromCodePoint()

String.includes()

String.indexOf()

String.lastIndexOf()

String.localeCompare()

String.matchAll()

String.padEnd()

String.padStart()

String.replace()

String.replaceAll()

String.search()

String.startsWith()

String.substring()

String.toLocaleLowerCase()

String.toLocaleUpperCase()

String.toLowerCase()

String.toString()

String.toUpperCase()

String.trimEnd()

String.trimStart()

String.valueOf()

Symbol.keyFor()

Array.indexOf()

Leírás

Visszatér az Array példány első azon elemének indexével, amelynek értéke megegyezik a metódus argumentumába írt paraméter értékével.

Szintaxis

indexOf(searchElement)
indexOf(searchElement, fromIndex)

Példa

const beasts = ['ant', 'bison', 'camel', 'duck', 'bison']
 
console.log(beasts.indexOf('bison'))
// Expected output: 1
 
console.log(beasts.indexOf('giraffe'))
// Expected output: -1
 
// Start from index 2
console.log(beasts.indexOf('bison', 2))
// Expected output: 4

in this article

Leírás
Szintaxis
Példa

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