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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Extract initials from 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.

charAt() method → returns the character at a specified index in a string.

toUpperCase() method → returns the value of the string converted to upper case.

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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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charAt() method returns the character at the given index.

If the index is out of range an empty string "" is returned.

const str6 = "hello";

str6.charAt(0); → "h"

str6.charAt(1); → "e"

str6.charAt(2); → "l"

str6.charAt(3); → "l"

str6.charAt(4); → "o"

str6.charAt(5); → "" not found

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toUpperCase() method returns a new string with all letters converted to upper case. The original string is unchanged.

const str7 = "hELlo wORLd";

str7.toUpperCase(); returns ↴

"HELLO WORLD" → uppercase

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Initialize a variable to hold the string to extract initials

const string1 = "Fear of missing out"; → user input

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Define a function getInitials to extract initials from a string

function getInitials(str) {}

The function takes a string as input str and returns the capitalized first character of each word concatenated into a new string. The original string remains unchanged.

Split the string into an array of words based on spaces.

const words = str.split(" ") words

Initialize an empty string to hold the initials.

let initials = "" initials

Loop through each word in the words array.

for (let word of words) {}

Append the first character of each word to the initials string, converting it to upper case.

Return the final initials string.

return initials

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Call the function with ↴

getInitials(string1);

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Extract initials from a string.