Day 3: Try, Catch, and Finally

Objective

In this challenge, we learn about strings and exceptions. Check out the attached tutorials for more details.

Task

Complete the reverseString function; it has one parameter, s. You must perform the following actions:

1. Try to reverse string s using the split, reverse, and join methods.
2. If an exception is thrown, catch it and print the contents of the exception’s message on a new line.
3. Print s on a new line. If no exception was thrown, then this should be the reversed string; if an exception was thrown, this should be the original string.

Input Format

Locked stub code in the editor reads variable s from stdin and passes it to the function.

Output Format

You must write two print statements using console.log():

1. Print the contents of a caught exception’s message on a new line. If no exception was thrown, this line should not be printed.
2. Print s on a new line. If no exception was thrown, then this should be the reversed string; if an exception was thrown, this should be the original string.

Sample Input 0

1

"1234"

##Sample Output 0

1

4321

Explanation 0

s = “1234” is a string type, so it can be reversed without throwing an exception. Thus, we print the reversed value, 4321, as our answer.

Sample Input 1

1

Number(1234)

##Sample Output 1

1
2

s.split is not a function
1234

Explanation 1

s = Number(1234) is not a string type, so it can’t be reversed using string functions. When we try to reverse it anyway, it throws an exception. We then catch the exception and print its message, which is s.split is not a function. Next, we finally print s which, because it wasn’t able to be reversed, is Number(1234).

Solutions

Solution 1

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

/*
 * Complete the isPositive function.
 * If 'a' is positive, return "YES".
 * If 'a' is 0, throw an Error with the message "Zero Error"
 * If 'a' is negative, throw an Error with the message "Negative Error"
 */
/*
 * Complete the reverseString function
 * Use console.log() to print to stdout.
 */
function reverseString(s) {
  try {
    s = s.split('').reverse().join('');
  } catch (e) {
    console.log('s.split is not a function');
  }

  console.log(s);
}

Solution 2

1
2
3
4
5
6
7
8
9
10
11

/*
 * Complete the reverseString function
 * Use console.log() to print to stdout.
 */
function reverseString(s) {
  typeof s !== 'string'
    ? console.log('s.split is not a function')
    : (s = s.split('').reverse().join(''));

  console.log(s);
}