Having an if statement change a string back and forth

Question

I am trying to make a button change a string from 'Mode One:' to 'Mode Two:', and when pressed again, changed back to 'Mode One:' and so on and so forth. However when I run this, it will change the first time to 'Mode Two:' but when I press it again, it will not go back to Mode One.

Here is my code:

Flip

<script>

    let currentMode = 'Mode one:'

    flip = () => {
        if(currentMode = 'Mode one:'){
            currentMode = 'Mode Two:'
            console.log(currentMode)
        }else if(currentMode = 'Mode Two:'){
            currentMode = 'Mode one:'
            console.log(currentMode)
        }
    }

</script>

Does this answer your question? [What is the difference between the \`=\` and \`==\` operators and what is \`===\`? (Single, double, and triple equals)](https://stackoverflow.com/questions/11871616/what-is-the-difference-between-the-and-operators-and-what-is-si) Also, this useful reference: [What does this symbol mean in JavaScript?](https://stackoverflow.com/questions/9549780/what-does-this-symbol-mean-in-javascript) — IMSoP, Feb 11 '22 at 14:31

Apollo79 · Answer 1 · 2022-02-11T14:34:42.153

1

In your if statement, your are assigning a value to a variable. The value of this operation is always true. To compare two values you need the == operator:

<script>

    let currentMode = 'Mode one:'

    flip = () => {
        if(currentMode == 'Mode one:'){
            currentMode = 'Mode Two:'
            console.log(currentMode)
        }else if(currentMode == 'Mode Two:'){
            currentMode = 'Mode one:'
            console.log(currentMode)
        }
    }

</script>

edited Feb 11 '22 at 14:34

answered Feb 11 '22 at 14:30

Apollo79

674
3
14

Oh, I got the wrong row :-) – Apollo79 Feb 11 '22 at 14:34

score 1 · Answer 2 · answered Feb 11 '22 at 14:31

Since you are using a single "=", that is not comparing values, it is assigning a value. You want to use "==" or "===":

if(currentMode == 'Mode one:'){
   currentMode = 'Mode Two:'
   console.log(currentMode)
}else if(currentMode == 'Mode Two:'){
   currentMode = 'Mode one:'
   console.log(currentMode)
}

Having an if statement change a string back and forth

2 Answers2