Day 3: Throw

Objective

In this challenge, we practice using throw and catch statements to work with custom error messages.

Task

Complete the isPositive function below. It has one integer parameter, a. If the value of a is positive, it must return the string YES. Otherwise, it must throw an Error according to the following rules:

• If a is 0, throw an Error with message = Zero Error.
• If a is negative, throw an Error with message = Negative Error.

Input Format

Locked stub code in the editor reads the following input from stdin and passes each value of a to the function as an argument:

The first line is an integer, n, denoting the number of times the function will be called with some a.

Each line i of the n subsequent lines contains an integer denoting some a.

Constraints

• 1 <= n <= 5
• -100 <= a <= 100

Output Format

If the value of a is positive, the function must return the string YES. Otherwise, it must throw an Error according to the following rules:

• If a is 0, throw an Error with message = Zero Error.
• If a is negative, throw an Error with message = Negative Error.

Sample Input 0

1
2
3
4

3
1
2
3

##Sample Output 0

1
2
3

YES
YES
YES

Explanation 0

Each of the given values is positive, so we return YES each time. The value returned during each function call is printed on a new line by locked stub code in the editor.

Sample Input 1

1
2
3
4

3
2
0
6

##Sample Output 1

1
2
3

YES
Zero Error
YES

Explanation 1

Locked stub code in the editor makes the following three calls to the isPositive function:

1. isPositive(2): This returns YES because 2 is positive.
2. isPositive(0): Because a = 0, we throw an Error with message = Zero Error. This is caught by the locked stub code and the value of its message is printed.
3. isPositive(6): This returns YES because 6 is positive.

Sample Input 2

1
2
3

2
-1
20

##Sample Output 2

1
2

Negative Error
YES

Explanation 2

Locked stub code in the editor makes the following two calls to the isPositive function:

1. isPositive(-1): Because a = -1, we throw an Error with message = Negative Error.
   This is caught by the locked stub code and the value of its message is printed.
2. isPositive(20): This returns YES because 20 is positive.

Solution

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/*
 * 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"
 */
function isPositive(a) {
  let result = 'YES';

  if (a < 0) {
    throw { message: 'Negative Error' };
  } else if (a === 0) {
    throw { message: 'Zero Error' };
  }

  return result;
}