Javascript array indexOf returns undefined - Stack Overflow

admin管理员组

文章数量:1425820

When calling my function checkIss(), issFullArray.indexOf(issToCheck) always returns undefined. I've run a .length, output the contents of issFullArray, I can't figure out why it's not working- the array looks fine to me. As you can see below, I've tried explicitly setting issArray as an array and copying the array returned by my getIssList()

function updateIss() {
    var issArray = [];

    var currService = current.u_business_service;
    var currIss = current.u_is_service;
    issArray = getIssList(currService).slice(); //getIssList() returns an arry
    if (checkIss(issArray, currIss) === false) {
        //do stuff
    }
}

function checkIss(issFullArray, issToCheck) {
    if (issFullArray.indexOf(issToCheck) < 0) {
        return false;
    } else {
        return true;
    }
}

When calling my function checkIss(), issFullArray.indexOf(issToCheck) always returns undefined. I've run a .length, output the contents of issFullArray, I can't figure out why it's not working- the array looks fine to me. As you can see below, I've tried explicitly setting issArray as an array and copying the array returned by my getIssList()

function updateIss() {
    var issArray = [];

    var currService = current.u_business_service;
    var currIss = current.u_is_service;
    issArray = getIssList(currService).slice(); //getIssList() returns an arry
    if (checkIss(issArray, currIss) === false) {
        //do stuff
    }
}

function checkIss(issFullArray, issToCheck) {
    if (issFullArray.indexOf(issToCheck) < 0) {
        return false;
    } else {
        return true;
    }
}

• javascript
• arrays
• undefined
• indexof

Share Improve this question Follow edited Feb 5, 2013 at 12:16 Cerbrus 73k1919 gold badges136136 silver badges150150 bronze badges asked Feb 5, 2013 at 12:13 user2042970user2042970 3311 gold badge11 silver badge33 bronze badges 6

• 3 Are you using a browser that supports array.indexOf. – adeneo Commented Feb 5, 2013 at 12:14
• 1 IE <=8, for example, doesn't support indexOf() for Arrays. – Tim Down Commented Feb 5, 2013 at 12:23
• I've tried IE9, Firefox 15 and Chrome 24. Are there actually browsers that wouldn't support indexOf()? Bit silly if you ask me... – user2042970 Commented Feb 5, 2013 at 12:24
• make the scope of issArray global and do not pass it to your checkIss() function and see whether it works – asifsid88 Commented Feb 5, 2013 at 12:27
• Thanks for your ments, but it appears it's the software that I'm coding for that doesn't support indexOf. I find it a bit odd that such a simple function isn't supported but heyho, I'll raise a bug and see what happens! – user2042970 Commented Feb 5, 2013 at 12:59

 |  Show 1 more ment

1 Answer 1

Sorted by: Reset to default 2

Easiest to just loop through the array and pare each value and return true if there is a match otherwise return false. Not much more code and works for all browsers.

function checkIss(issFullArray, issToCheck) {
    for(i=0; i<issFullArray.length; i++) {
        if(issFullArray[i]==issToCheck) {
            return true;
        }
    }
    return false;
}

本文标签： Javascript array indexOf returns undefinedStack Overflow