So I'm trying to build code where the user is prompted for "rock", "paper", or "scissors", and then that is compared with a random computer choice. The computer's choice is deemed by a random value between 0 and 1. Our compare function passes through both of these choices and compares their value to return an output, telling which hand signal wins. I am getting a syntax error but cannot seem to figure out what I'm missing.
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
} else if (computerChoice <= 0.67) {
computerChoice = "paper";
} else {
computerChoice = "scissors";
}
var compare = function(choice1, choice2) {
if (choice1 === choice2) {
return "The result is a tie!";
} else if (choice1 === "rock") {
if (choice2 === "scissors") {
return "rock wins";
} else {
return "paper wins";
}
} else if (choice1 === "paper") {
if (choice2 === "rock") {
return "paper wins";
} else {
return "scissors wins";
}
} else(choice1 === "scissors") {
if (choice2 === "paper") {
return "scissors wins";
} else {
return "rock wins";
}
}
}
console.log(compare(userChoice, computerChoice));
You have a condition for your else statement. Either remove it or add the if.
} else if (choice1 === "scissors") {
if (choice2 === "paper") {
return "scissors wins";
} else {
return "rock wins";
}
}
else (choice1 === "scissors") { is the issue. Either do an else if (...) { or an else {
.
By the way, the syntax error tells you the exact error. In the Chrome developer tools, I only had to click on the error in the console to see the line.
else (choice1 === "scissors") {
is an illegal statment.
else if
expects a conditional.
else
should not have one.
Related
I have no idea where the error is anymore. It was first saying that I had an unexpected identifier, then I had an unmatched }, now I have an illegal return statement. I just need some help. Thanks.
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
} else if (computerChoice <= 0.67) {
computerChoice = "paper";
} else {
computerChoice = "scissors";
}
console.log("Computer: " + computerChoice);
var compare = function(choice1, choice2) {
if (choice1 === choice2) {
return "The result is a tie!";
} else if (choice1 === "rock") {
if (choice2 === "scissors") {
return "rock wins";
} else {
return "paper wins";
}
if (choice2 === "rock") {
return "paper wins";
} else {
return "scissors wins";
} else if (choice1 === "paper") {
if (choice2 === "rock") {
return "paper wins";
} else {
return "scissors wins";
}
}
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
} else if (computerChoice <= 0.67) {
computerChoice = "paper";
} else {
computerChoice = "scissors";
}
console.log("Computer: " + computerChoice);
var compare = function (choice1, choice2) {
if (choice1 === choice2) {
return "The result is a tie!";
} else if (choice1 === "rock") {
if (choice2 === "scissors") {
return "rock wins";
} else {
return "paper wins";
}
if (choice2 === "rock") {
return "paper wins";
} else if (choice1 === "paper") {
if (choice2 === "rock") {
return "paper wins";
} else {
return "scissors wins";
}
}
}
}
Properly indented code can help find missing curly braces. By the time that something is indented 4 times, it's time to see if it can be refactored.
For example:
The first if has a return. There is no reason to have an "else if" after that. That will get rid of one indent. Same can be said of ("choice2 === "rock"). Trust that when a return is written that it will actually return.
I have the code for a basic "rock, paper, scissor" game in JS. It works with a promt but I would like to be able to make your choices with buttons. I would like to use "getElementById" and "addEventListener("click")". Could anyone point me in the right direction?
HTML:
<button id ="rock"> Rock </button>
Paper
Scissor
JavaScript:
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
} else if(computerChoice <= 0.67) {
computerChoice = "paper";
} else {
computerChoice = "scissors";
} console.log("Computer: " + computerChoice);
var compare = function (choice1, choice2) {
if (choice1 === choice2) {
return "The result is a tie!";
}
else if (choice1 === "rock") {
if (choice2 === "scissors") {
return "rock wins";
}
else {
return "paper wins";
} if (choice1 === "paper") {
if (choice2 === "rock") {
return "paper wins";
}
else {
return "scissors wins";
} if (choice1 === "scissors") {
if (choice2 === "rock") {
return "rock wins";
} else if (choice2 === "paper") {
return "scissors wins";
}
}
}
}
}
compare (userChoice, computerChoice);
Use the onclick event handler (documentation) in several blocks like this:
document.getElementById('rock').onclick = function(e){
userChoice = 'rock'
}
Here is an example (click "run code snippet"):
document.getElementById('rock').onclick = user;
document.getElementById('paper').onclick = user;
document.getElementById('scissors').onclick = user;
function user(){
var userChoice = this.id;
console.log("User: " + userChoice)
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
}else if(computerChoice <= 0.67) {
computerChoice = "paper";
}else{
computerChoice = "scissors";
};
console.log("Computer: " + computerChoice);
console.log(compare(userChoice, computerChoice));
function compare(choice1, choice2) {
if (choice1 === choice2) {
return "The result is a tie!";
}
if (choice1 === "rock") {
if (choice2 === "scissors") {
return "rock wins";
}else{
return "paper wins";
}
}
if (choice1 === "paper") {
if (choice2 === "rock") {
return "paper wins";
} else {
return "scissors wins";
}
}
if (choice1 === "scissors") {
if (choice2 === "rock") {
return "rock wins";
} else {
return "scissors wins";
}
}
}
}
<button id="rock">Rock</button>
<button id="paper">Paper</button>
<button id="scissors">Scissor</button>
PS: your function compare was returning undefined for some cases.
I'm trying to learn javascript and this lesson is having me create a rock, paper, scissors game. It is asking for me to:
Call your function and pass in userChoice and computerChoice as your two arguments.
I am not sure how to pass in userChoice and computer Choice. I tried doing this:
console.log(compare + userChoice + computerChoice)
But obviously it isn't correct.
What am I doing wrong??
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
} else if(computerChoice <= 0.67) {
computerChoice = "paper";
} else {
computerChoice = "scissors";
} console.log("Computer: " + computerChoice);
var compare = function(choice1, choice2) {
if (choice1 === choice2) {
return "The result is a tie!";
} else if (choice1 === "rock") {
if (choice2 === "scissors") {
return "rock wins";
} else {
"paper wins";
}
} else if (choice1 === "paper") {
if (choice2 === "rock") {
return "paper wins";
} else {
return "scissors wins";
}
} else if (choice1 === "scissors") {
if (choice2 === "rock") {
return "rock wins";
} else {
return "scissors wins";
}
}
}
console.log(compare + userChoice + computerChoice)
You're VERY close, arguments are passed to functions like this:
compare(userchoice, computerChoice);
This question already has an answer here:
javascript, creating a rock, paper, scissors game [closed]
(1 answer)
Closed 8 years ago.
I'm new to Java script and coding. I am trying to figure out a syntax error in Rock, paper, scissors, lizard, spock which is messing up my code. When I compile the code it says "SyntaxError: Unexpected token {" and I can't figure out why and where I messed up. Thanks for the help!
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice <= 0.20) {
computerChoice = "rock";
}
else if (computerChoice <= 0.40) {
computerChoice = "paper";
}
else if (computerChoice <= 0.60) {
computerChoice = "scissors";
}
else if (computerChoice <= 0.80) {
computerChoice = "lizard";
}
else {
computerChoice = "spock";
}
console.log("Computer: " + computerChoice);
var compare = function (choice1, choice2) {
if (choice1 === choice2) {
return "The result is a tie!";
}
else if (choice1 === "rock") {
if (choice2 === "scissors") {
return "rock wins";
}
else if (choice2 === "paper") {
return "paper wins";
}
else if (choice2 === "lizard") {
return "rock wins";
}
else {
return "spock wins";
}
}
else if (choice1 === "paper") {
if (choice2 === "rock") {
return "paper wins";
}
else if (choice2 === "scissors") {
return "scissors win";
}
else if (choice2 === "lizard") {
return "lizard wins";
}
else {
return "paper wins";
}
}
else if (choice1 === "scissors") {
if (choice2 === "rock") {
return "rock wins";
}
else if (choice2 === "paper") {
return "scissors win";
}
else if (choice2 === "lizard") {
return "scissors win";
}
else {
return "spock wins";
}
}
else if (choice1 === "lizard") {
if (choice2 === "rock") {
return "rock wins";
}
else if (choice2 === "scissors") {
return "scissors win";
}
else if (choice2 === "paper") {
return "lizard wins";
}
else {
return "lizard wins";
}
}
else {
if (choice2 === "rock") {
return "spock wins";
}
else if (choice2 === "paper") {
return "paper wins";
}
else if (choice2 === "scissors") {
return "spock nigga wins";
}
else {
return "lizard wins";
}
}
};
compare(userChoice, computerChoice);
You're missing a closing parenthesis :
else if (choice2 === "scissors"
I am new to js, I just wrote the basic function below based on the rock, paper, scissors game. For some reason the result of the compare function is always showing up as a
"draw" rather than the other results. What am I doing wrong here?
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
} else if (computerChoice <= 0.67) {
computerChoice = "paper";
} else {
computerChoice = "scissors";
}
choice1 = userChoice;
choice2 = computerChoice;
var compare = function (choice1, choice2) {
if (choice1 == choice2) {
return "draw!";
}
if (choice1 == "rock") {
if (choice2 == "scissors") {
return "rock wins!";
} else {
return "paper wins!";
}
}
if (choice1 == "paper") {
if (choice2 == "scissors") {
return "scissors wins!";
} else {
return "paper wins!";
}
}
if (choice1 == "scissors") {
if (choice2 == "rock") {
return "rock wins!";
} else {
return "scissors wins!";
}
}
};
compare();
Thanks, Us
You're calling compare without parameters:
compare();
Therefore choice1 and choice2 both equals undefined and your game will always end up as draw.
You should try calling your compare function like this:
compare(userChoice, computerChoice);
If you define a function, the parameter list defines the names of the given variables within the scope of the function. It's not a naming convention for the variables which should be available in the function itself.
You have defined the function with two arguments:
var compare = function (choice1, choice2)
However you have invoked it with 0.
Try specifying the choices:
compare("rock", "paper");
You can't turn on function only by typing func_name() without arguments, thats like "dry shot". Read about function declaring
var userChoice = prompt("Do you choose rock, paper or scissors?");
var computerChoice = Math.random();
if (computerChoice < 0.34) {
computerChoice = "rock";
} else if (computerChoice <= 0.67) {
computerChoice = "paper";
} else {
computerChoice = "scissors";
}
choice1 = userChoice;
choice2 = computerChoice;
function compare (choice1, choice2) {
if (choice1 == choice2) {
return "draw!";
};
if (choice1 == "rock") {
if (choice2 == "scissors") {
return "rock wins!";
} else {
return "paper wins!";
}
}
if (choice1 == "paper") {
if (choice2 == "scissors") {
return "scissors wins!";
} else {
return "paper wins!";
}
}
if (choice1 == "scissors") {
if (choice2 == "rock") {
return "rock wins!";
} else {
return "scissors wins!";
}
}
};
compare(choice1, choice2);