Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
381 views
in Technique[技术] by (71.8m points)

titanium - How to check if an array index exists or not in javascript?

I am working with Titanium, my code looks like this:

var currentData = new Array();
if(currentData[index]!==""||currentData[index]!==null||currentData[index]!=='null')
{
    Ti.API.info("is exists  " + currentData[index]);
    return true;
}
else
{   
    return false;
}

I am passing an index to the currentData array. I still can't detect a non-existing index using the above code.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Use typeof arrayName[index] === 'undefined'

i.e.

if(typeof arrayName[index] === 'undefined') {
    // does not exist
}
else {
    // does exist
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...