How can I make Javascript parameters default to something if not present?

Question

I have this function:

this.checkButton = function (buttonName, element, expectedPresent, expectedEnabled) {
    var enabledCheck = expectedEnabled ? "enabled" : "disabled";
    it('Find a ' + buttonName + ' button and check it is ' + enabledCheck, function () {
        expect(element.isPresent()).toBe(expectedPresent);
        expect(element.isEnabled()).toBe(expectedEnabled);
    });
}

Is there a way I can make this so that if the function is called without the last two parameters then those parameters will both default to true?

score 2 · Answer 1 · answered Jul 12 '14 at 07:22

Compare the parameters to undefined to know if they are present:

    this.checkButton = function (buttonName, element, expectedPresent, expectedEnabled) {

        if(expectedPresent === undefined) {
            expectedPresent = true;
        }
        if(expectedEnabled === undefined) {
            expectedEnabled = true;
        }
        var enabledCheck = expectedEnabled ? "enabled" : "disabled";
        it('Find a ' + buttonName + ' button and check it is ' + enabledCheck, function () {
            expect(element.isPresent()).toBe(expectedPresent);
            expect(element.isEnabled()).toBe(expectedEnabled);
        });
    }

score 0 · Accepted Answer · answered Jul 12 '14 at 07:21

0

If I understood what you want.

Try to say in starting of function.

expectedPresent = (expectedPresent==undefined) ? true : expectedPresent;
expectedEnabled = (expectedEnabled==undefined) ? true : expectedEnabled;

I hope this helps.

answered Jul 12 '14 at 07:21

Mritunjay

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That doesn't work. At all. – Robby Cornelissen Jul 12 '14 at 07:22
This way it's not possible to pass `expectedPresent` as `false`. – dfsq Jul 12 '14 at 07:22
use `===` instead of `==`. – Barmar Jul 12 '14 at 07:25
@Barmar sorry for asking, but how does that help? – Mritunjay Jul 12 '14 at 07:26
Never mind, I was wrong. – Barmar Jul 12 '14 at 07:27
ok thank you all of you for your suggestions – Mritunjay Jul 12 '14 at 07:30
@Robby / Others - Do you think this is a good solution now ? – Jul 12 '14 at 07:30
http://stackoverflow.com/a/894877/3558960 – Robby Cornelissen Jul 12 '14 at 07:34

How can I make Javascript parameters default to something if not present?

2 Answers2