Iterator Methods Cheat Sheet

it-methods-cheat-sheet.md

Iterator Methods Cheat Sheet

Contents:

• concat
• Abbreviation
• Superscript
• unshift

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concat()

• The concat() method is used to join two or more arrays.

• This method does not change the existing arrays, but returns a new array, containing the values of the joined arrays.

Ex:

var hege = ["Cecilie", "Lone"];
var stale = ["Emil", "Tobias", "Linus"];
var kai = ["Robin"];
var children = hege.concat(stale, kai);
//children === [Cecilie, Lone, Emil, Tobias, Linus, Robin]

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filter()

• The filter() method creates an array filled with all array elements that pass a test (provided as a function).

• syntax: array.filter(function(currentValue, index, arr), thisValue)

Example 1

var words = ['spray', 'limit', 'elite', 'exuberant', 'destruction']

const result = words.filter(word => word.length > 6);

//output: ['exuberant', 'destruction', 'present']

Example 2

var fruits = ['apple', 'banana', 'grapes', 'mango', 'orange'];

function filterItems(arr, query) {
  return arr.filter(element => {
    return element.toLowerCase().indexOf(query.toLowerCase())
  });
}

console.log(filterItems(fruits, 'ap')); // ['apple', 'grapes']
console.log(filterItems(fruits, 'an')); // ['banana', 'mango', 'orange']

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find()

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findIndex()

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forEach()

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includes()

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indexOf()

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join()

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keys()

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map()

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pop()

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push()

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reduce()

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reverse()

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shift()

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slice()

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sort()

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splice()

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toString()

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unshift()

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