How to make first letter of a string uppercase in JavaScript ?

In this article, we will convert the first letter of a string to uppercase in Javascript. There are a number of ways to capitalize the first letter of the string in JavaScript. 

• Using toUpperCase() method
• Using slice() method
• Using charAt() method
• Using replace() method

JavaScript toUpperCase() Function: This function applies on a string and changes all letters to uppercase. 

Syntax:

string.toUpperCase()

JavaScript slice() Function: This function applies to a string and slices it according to the passed parameter. 

Syntax:

string.slice(start, end)

Example: This example uses the slice() method to convert the first letter to uppercase.

Javascript

function capitalizeFLetter() {
    let string = 'geeksforgeeks';
    console.log(string[0].toUpperCase() +
        string.slice(1));
}
capitalizeFLetter()

Output

Geeksforgeeks

JavaScript charAt() Function: This charAt() function returns the character at a given position in the string. 

Syntax:

string.charAt(index)

Example: This example uses charAT() method to make the first letter of a string uppercase.

Javascript

function capitalizeFLetter() {
    let string = 'geeksforgeeks';
    console.log(string.charAt(0).toUpperCase() +
        string.slice(1));
}
capitalizeFLetter()

Output

Geeksforgeeks

JavaScript replace() Function: This is a built-in function in JavaScript that is used to replace a slice of a string with another string or a regular expression. The original string will not be affected. 

Syntax:

str.replace(A, B)

The below examples show the conversion to uppercase using the above-described methods.

Example: This example uses string.replace() method to make the first letter of a string uppercase.

Javascript

function capitalizeFLetter() {
    let string = 'geeksforgeeks';
    console.log(string.replace(/^./, string[0].toUpperCase()));
}
capitalizeFLetter()

Output

Geeksforgeeks