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JavaScript

Posted by Rod Sanati
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Rod Sanati
Full Stack JavaScript Techdegree Graduate 20,177 Points

Why can you not use the series of keywords "if, else if, else" for our item.key conditional statements?

In the video we learn how to add multiple conditional statements for the point values of the items in the game -- if, else if, else if, for 'coin', 'poison', 'star', respectively.

But lower in the game.js file, regarding applying animation to movement keys being pressed, you are allowed to use the series of conditional keywords -- if, else if, else.

When I try to do the same for item values it just breaks the code and the game doesn't load. Is the 2nd case for a different usage? Could you not apply the 2nd series of conditional keywords to the item/values used in the video?

https://teamtreehouse.com/library/control-the-flow-with-conditional-statements

Thank you.

Joseph Wasden
Joseph Wasden
20,407 Points

Could you link to the video in question?

2 Answers

Joseph Wasden
Joseph Wasden
20,407 Points

Hm... not quite sure what's the problem.

When you write your If()...else if()... else statement, are you accidentally including a conditional statement after the else keyword? In other words, are you following your else statement with parenthesis that are to check a condition? because if so, that may be breaking the code.

else is the code to execute if the if statement preceding it fails. That is it's condition: we do not outline an additional condition for the else keyword.

Rod Sanati
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Rod Sanati
Full Stack JavaScript Techdegree Graduate 20,177 Points

I think that sums it up. I wasn't realizing that in the 2nd block of code (pre-written), that the "else" was by itself and wasn't a conditional statement. They were all conditional statements in the first block of code.

Thank you.

Joseph Wasden
Joseph Wasden
20,407 Points

Great! Glad we could figure it out.

Rod Sanati
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.a{fill-rule:evenodd;}techdegree seal-36
Rod Sanati
Full Stack JavaScript Techdegree Graduate 20,177 Points
Rod Sanati
.a{fill-rule:evenodd;}techdegree seal-36
Rod Sanati
Full Stack JavaScript Techdegree Graduate 20,177 Points

https://teamtreehouse.com/library/control-the-flow-with-conditional-statements

Strange, I thought this question would be posted underneath the specific video lesson. I must have not posted properly, but here is the video.

Code we were creating in the video:

 // when the player collects an item on the screen
function itemHandler(player, item) {
item.kill();
if(item.key === 'coin'){
currentScore = currentScore + 10;
}
else if(item.key === 'poison'){
     currentScore = currentScore - 25;
}
else if(item.key === 'star'){
     currentScore = currentScore + 25;
}
if (currentScore === winningScore) {
  createBadge();
}

}

Code later on in the game.js file where the other keywords are used:

// is the left cursor key presssed?
if (cursors.left.isDown) {
  player.animations.play('walk', 10, true);
  player.body.velocity.x = -300;
  player.scale.x = - 1;
}
// is the right cursor key pressed?
else if (cursors.right.isDown) {
  player.animations.play('walk', 10, true);
  player.body.velocity.x = 300;
  player.scale.x = 1;
}
// player doesn't move
else {
  player.animations.stop();
}

if (jumpButton.isDown && (player.body.onFloor() || player.body.touching.down)) {
  player.body.velocity.y = -400;
}
// when the player winw the game
if (won) {
  winningMessage.text = "YOU WIN!!!";
}

}