Node.js if statement not working as expected

Question

I am learning javascript & Node.js. For some reason this IF statement is not working as I would've expected...
I cannot figure out how to solve this...

My code:

process.stdin.setEncoding('utf8');                      //Set UTF charcode

process.stdin.on('readable', () => {                    //Event fires when there's input
    var readConsole = process.stdin.read();             //Receive the input from console

    if(readConsole != null) {
        readConsole.trim().replace(/\r?\n|\r/g, " ");   //Trim input and remove line breaks

        process.stdout.write('Input: ' + readConsole);  //Output the input

        if(readConsole == "quit") {
            process.exit();
        }
    }
});

But for some reason, whenever I type "quit" in the console, it does not respond.

Here is an image of the problem:

Consider getting in the habit of using `===` instead of `==`. — Joe White, Jan 15 '17 at 02:52
@Joe white; why do I need to use 3 equals? I thought 1 was for setting variables, 2 was for if statements etc. and 3 for if statements with true or false? Isn't that the case?? — Kerwin Sneijders, Jan 15 '17 at 09:07
`=` is indeed for assignment. `==` and `===` are both comparison operators; their behavior is identical except that `==` does type coercion, which is almost never a good thing. See http://stackoverflow.com/a/359509/87399. — Joe White, Jan 17 '17 at 23:10
@JoeWhite Thanks! I never knew that! I'll start using that from now on! :) — Kerwin Sneijders, Jan 18 '17 at 23:19

Keammoort · Accepted Answer · 2017-01-15T01:33:58.823

4

Both trim() and replace() return a new string, but you are not assigning that value to any variable. You probably want to remove extra characters, not replace them with spaces (thanks @fvgs). Try:

readConsole = readConsole.trim().replace(/\r?\n|\r/g, "");

edited Jan 15 '17 at 01:33

answered Jan 15 '17 at 01:16

Keammoort

3,075
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The replacement string should probably be `""`, otherwise the condition in the if statement will need to be `readConsole == "quit "`. – fvgs Jan 15 '17 at 01:22
Owh, I did that at first. but removing the spaces worked this way too.... Anyway, thanks man 10/10!! – Kerwin Sneijders Jan 15 '17 at 09:05

Node.js if statement not working as expected

1 Answers1