Strings containing digits in JavaScript

Suppose we have a string containing only digits:

javascriptlet test = '12345'; // string with digits

Let's find, for example, the sum of its first and second characters:

javascriptlet test = '12345';
alert(test[0] + test[1]); // shows '12' - concatenates like strings

As you can see, the characters in our string are also strings and are concatenated as strings. Let's say we want to sum them as numbers. We use the function Number for this aim:

javascriptlet test = '12345'; // string
alert(Number(test[0]) + Number(test[1])); // shows 3