Day 16: Exceptions - String to Integer

Objective

Today, we’re getting started with Exceptions by learning how to parse an integer from a string and print a custom error message. Check out the Tutorial tab for learning materials and an instructional video!

Task

Read a string, S, and print its integer value; if S cannot be converted to an integer, print Bad String.

Note: You must use the String-to-Integer and exception handling constructs built into your submission language. If you attempt to use loops/conditional statements, you will get a 0 score.

Input Format

A single string, S.

Constraints

• 1 <= |S| <= 6, where |S| is the length of string S.
• S is composed of either lowercase letters (a - z) or decimal digits (0 - 9).

Output Format

Print the parsed integer value of S, or Bad String if S cannot be converted to an integer.

Sample Input 0

1

3

Sample Output 0

1

3

Sample Input 1

1

za

Sample Output 1

1

Bad String

Explanation

Sample Case 0 contains an integer, so it should not raise an exception when we attempt to convert it to an integer. Thus, we print the 3.

Sample Case 1 does not contain any integers, so an attempt to convert it to an integer will raise an exception. Thus, our exception handler prints Bad String.

Solution

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/*
 * You can use the following pseudocode:
 *
 * `S` = read string from stdin.
 * try {
 *     `N` = numeric value of `S`.
 *     
 *     If `N` is `NaN` or `undefined`, then some exception must be thrown,
 *     you can write the following withtout using conditional statement:
 *     <condition to return true when `N` is `NaN` or `undefined`> && an_undefined_function_call()
 *
 *     print `N`
 * } catch (err) {
 *     print `Bad String`.
 * }
 */

function main() {
    const S = readLine();

    try {
        console.log(parseInt(S).toString().replace('NaN', 'Bad String'));
    } catch (e) {
        console.log("Bad String");
    }
}