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JavaScript JavaScript Basics (Retired) Making Decisions with Conditional Statements Improving the Random Number Guessing Game

Can I use global variables within the nested If statement?

I was analyzing the code from this task and I was wondering if the nested if is always validating the variable that we passed at the main if ?

Can I do it like this, or It would be harder to read / bad practice?

var correctGuess = false;
var randomNumber = Math.floor(Math.random() * 6 ) + 1;
var guess = prompt('I am thinking of a number between 1 and 6. What is it?');
var guessMore = prompt('Try again. The number I\'m thinking of, is more than ' + guess);
var guessLess = prompt('Try again. The number I\'m thinking of, is less than ' + guess);

if (parseInt(guess) === randomNumber ) {
  correctGuess = true;
} else if (parseInt(guess) < randomNumber) {
    if (parseInt(guessMore) === randomNumber) {
    // var guessMore was here. 
    correctGuess = true;
  }                         
} else if (parseInt(guess) > randomNumber) {
    if (parseInt(guessLess) === randomNumber) {
    // var guessLess was here. 
    correctGuess = true;
  }
}

if ( correctGuess ) {
    document.write('<p>You guessed the number!</p>');
} else {
    document.write('<p>Sorry. The number was ' + randomNumber + '.</p>');
}

Thank you in advance. =)

1 Answer

Steven Parker
Steven Parker
229,981 Points

Global variables are available at any level of nesting as long as they have not been "shadowed" by a variable with the same name in a closer scope.

The "best practice" approach with variables is to declare them in the smallest scope that is adequate for how they are used.

But more than variable scope, the issue here is that the "prompt" statements are no longer controlled by the "if" conditions, so they will both be performed before the values are evaluated. This alters the intended performance of the program.