javascript - ReferenceError: Invalid left-hand side in assignment

Question

my code for a rock paper scissors game (called toss) is as follows:

var toss = function (one,two) {
    if(one = "rock" && two = "rock") {
        console.log("Tie! Try again!");
    }
    // more similar conditions with `else if`
};

When I enter in the parameters

toss("rock","rock")

I get this error code:

"ReferenceError: Invalid left-hand side in assignment"

How to fix it? What this error means and what other cases when this error can happen?

Answer 1

You have to use == to compare (or even ===, if you want to compare types). A single = is for assignment.

if (one == 'rock' && two == 'rock') {
    console.log('Tie! Try again!');
}