Suppose that when iterating over numbers,
we want to get some digit from these numbers.
For example, we want to make a number be
displayed on the console if its first digit
is 1
or 2
.
I remind you that you can’t refer to the characters of a number directly, that is, it won’t work like this:
for (let i = 1; i <= 100; i++) {
if (i[0] == 1 || i[0] == 2) { // that won't work
console.log(i);
}
}
First you need to convert the number to a string and then get a certain character of the returned string, like this:
for (let i = 1; i <= 100; i++) {
let str = String(i); // converting number to string
if (str[0] === '1' || str[0] === '2') {
console.log(i);
}
}
Loop through the numbers from 10
to 1000
and output the first
digit of each number to the console.
Loop through the numbers from 10
to 1000
and output the sum of the
first and second digits of each number
to the console.
Loop through the numbers from 10
to 1000
and output those numbers
whose first digit is equal to 1
.
Loop through the numbers from 10
to 1000
and display those numbers
whose sum of the first two
digits is 5
.