Nested if-else constructs in JavaScript
The if-else constructs can be
nested arbitrarily. See an example:
let num = 3;
if (num >= 0) {
if (num <= 5) {
console.log('less than or equal to 5');
} else {
console.log('greater than 5');
}
} else {
console.log('less than zero');
}
Let the variable num store a number.
If this number falls within the range from
10 to 99, then find the sum of
the digits of this number.
If the resulting sum is less than or equal
to 9, then print a message that the
sum of the digits is single-digit, otherwise,
print a message that the sum of the
digits is two-digit.
