Let now we store not a number in quotes in
a variable, but just a number. In this case,
an attempt to access its individual character
will return undefined
,
since such an access only works for strings:
let test = 12345;
alert(test[0]); // shows undefined
let's convert our number to a string to solve the problem:
let test = String(12345); // string
alert(test[0]); // shows '1' - everything works
Suppose now we want to find the sum of the first two digits:
let test = String(12345); // string
alert(test[0] + test[1]); // shows '12' - concatenates like strings
Let's add the function Number
so
that the characters are summed as numbers:
let test = String(12345); // string
alert(Number(test[0]) + Number(test[1])); // shows 3
I remind you that a problem of this kind will arise only with summation. When multiplying, for example, conversion to numbers can be omitted:
let test = String(12345); // string
alert(test[1] * test[2]); // shows 6
The number given is 12345
.
Find the sum of the digits of this number.
The number given is 12345
.
Find the product of the digits of this number.
The number given is 12345
.
Rearrange the digits of this number in reverse order.