Strings are a sequence of zero or more characters written inside quotes used to represent text.

Strings may consist of letters, numbers, symbols, words, or sentences.

Strings are immutable, they cannot be changed.

Each character in a string has an index.

The first character will be index 0 the second character will be index 1 and so on.

There are two ways to access an individual character in a string.

charAt() method

const str1 = "abc"; string

str1.charAt(0); character at index 0 → "a"

str1.charAt(1); character at index 1 → "b"

str1.charAt(2); character at index 2 → "c"

str1.charAt(3); character at index 3 → "" index not found

Alternatively use at() or slice() methods

bracket notation []

const str2 = "abc"; string

str2[0]; character at index 0 → "a"

str2[1]; character at index 1 → "b"

str2[2]; character at index 2 → "c"

str2[3]; character at index 3 → undefined index not found

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Arrays are used to store multiple values in a single variable.

Each value is called an element, and each element has a numeric position in the array, known as its index.

Arrays are zero-indexed, meaning the first element is at index 0, the second at index 1, and so on.

Arrays can contain any data type, including numbers, strings, and objects.

const arr1 = [2, 4, 6]; array

arr1[0]; element at index 0 → 2

arr1[1]; element at index 1 → 4

arr1[2]; element at index 2 → 6

arr1[3]; element at index 3 → undefined index not found

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Numbers are used to represent both integer and floating-point values.

Numbers are most commonly expressed in literal forms like 255 or 3.14159 ↴

let num1 = 5; → number

let num2 = 2.5; → number

let num3 = num1 + num2;

console.log(num3); returns ↴

7.5 → number

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Find longest word in a string using ↴

for...of loop → iterates through the values of an iterable object, such as an array, string, or map.

split() method → splits a string into an array of substrings.

length property → returns the length of a string.

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for...of loop iterates through the values of an iterable object, such as an Array, String, Set, Map, ...

syntax

for (variable of iterable) {}

variable holds the current value of the iteration.

of keyword indicates that the loop should iterate over the values of the iterable.

iterable object that is iterable, such as an Array, String, Set, Map, ...

Iterate over each character in the string.

const str3 = "ABC";

for (const char of str3) {

console.log(char);

} returns ↴

A

B

C → printed to console

The loop will run three times, once for each character in the string.

On each iteration, the value of the current element is stored in the variable char

For each iteration of the loop, the current value of char is printed to the console.

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split() method splits a string into an array of substrings based on a specified separator (delimiter). The original string is unchanged.

const str4 = "Hello"; → string

str4.split(""); returns ↴

["H", "e", "l", "l", "o"] → array

const str5 = "hello world"; → string

str5.split(" "); returns ↴

["hello", "world"] → array

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length property returns the number of characters in a string.

const str6 = "Hello World";

str6.length; returns ↴

11 → there are 11 characters in the string

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Initialize a variable to hold the string to find the longest word.

const string1 = "The quick brown fox jumped over the lazy dog"; → user input

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Define a function findLongestWord to find the longest word in a string.

function findLongestWord(str) {}

The function takes a string as input str and returns the longest word found in that string. The original string remains unchanged.

Split the string str into an array of words using the space character " " as a delimiter.

const words = str.split(" ") words

Initialize a variable to hold the longest word found.

let longest = "" longest

Iterate through each word in the words array.

for (let word of words) {}

Check if the current word is longer than the longest word found so far.

if (word.length > longest.length) {}

If true, update the longest word if the current word is longer.

longest = word

Return the longest word found.

return longest

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Call the function with ↴

findLongestWord(string1);

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Find longest word in a string.