what does charat do in javascript code example

Example 1: how to get the first character of a string in javascript

let str = 'John Wick'
let firstChar = str.charAt(0) 
console.log(firstChar); // "J"

Example 2: javascript charat

/*
charAt() method
This method takes in a string and an index as input
and returns the character at that position in the specified string
*/

myString = "Hello World!";

console.log(myString.charAt(0)); // outputs "H"
console.log(myString.charAt(5)); // outputs " "
console.log(myString.charAt(8)); // outputs "r"
// If the specified index is bigger or equal to the length of the string,
// the output will be "".
console.log(myString.charAt(23)); // outputs ""

Example 3: string charat javascript

let str = new String("This is string"); 
console.log("str.charAt(0) is:" + str.charAt(0)); 
console.log("str.charAt(1) is:" + str.charAt(1)); 
console.log("str.charAt(2) is:" + str.charAt(2)); 
console.log("str.charAt(3) is:" + str.charAt(3)); 
console.log("str.charAt(4) is:" + str.charAt(4)); 
console.log("str.charAt(5) is:" + str.charAt(5));

output:

str.charAt(0) is:T 
str.charAt(1) is:h 
str.charAt(2) is:i 
str.charAt(3) is:s 
str.charAt(4) is:
str.charAt(5) is:i