Step by Step solution about How to resolve the algorithm Assertions step by step in the JavaScript programming language

This JavaScript code defines a function check() that verifies if the variable answer is a number and equal to 42. If any of these conditions is not met, it throws an exception, assigns 42 to answer, and finally logs answer to the console.

Detailed Breakdown:

1. Function check():

   • This function takes no arguments.

2. try-catch-finally Block:

   • try Block:
     • It attempts to execute the code within the try block.
     • Inside the try block, there are two conditional statements:
       • The first if statement checks if isNaN(answer) is true, which means answer is not a number. If it is not a number, it throws an exception with the message '$answer is not a number'.
       • The second if statement checks if answer is not equal to 42. If it is not 42, it throws an exception with the message '$answer is not 42'.
   • catch Block:
     • If an exception is thrown within the try block, the catch block is executed.
     • In this case, the catch block logs the error message to the console using console.log(err).
     • It then assigns the value 42 to the answer variable.
   • finally Block:
     • The finally block is executed regardless of whether an exception was thrown or not.
     • In this case, the finally block logs the value of answer to the console using console.log(answer).

3. Function Invocation and Result:

   • The check() function is invoked two more times with different values for answer.
   • In the second invocation, answer is assigned the string value 'fourty two'. Since it is not a number, an exception is thrown, and the catch block executes, assigning 42 to answer and logging it to the console.
   • In the third invocation, answer is assigned the number 23. This time, the try block executes successfully without throwing an exception, and the finally block logs the value 42 to the console.

Console Output:

$answer is not a number
42
$answer is not a number
42
$answer is not 42
42

Note: The console.count('try') statements are used to count the number of times the try block is executed. In this case, it executes three times, once for each invocation of the check() function.

function check() {
  try {
    if (isNaN(answer)) throw '$answer is not a number';
    if (answer != 42)  throw '$answer is not 42';
  }
  catch(err) {
    console.log(err);
    answer = 42;
  }
  finally { console.log(answer); }
}

console.count('try'); // 1
let answer;
check();

console.count('try'); // 2
answer = 'fourty two';
check();

console.count('try'); // 3
answer = 23;
check();