Javascript/Jquery 数组搜索

Question

I'm working on an application that uses nested arrays in Javascript. I have an array like this:

var a = ["Once upon a time there was a man."];

    a[1] = ["He was tall."];
           a[1][1] = ["He often bumped his head."];

    a[2] = ["He was short."];
           a[2][1] = ["He couldn't reach high shelves."]

Is there an easy way to figure out what level of an array a value is at? I'd like to be able to input "He often bumped his head" and have it return "a[1][1]" (or if I input "He was short" I'd get back "a[2]"). The arrays will be of indeterminate and fluctuating size.

Thanks in advance for any help with this. I'm new to javascript and jquery, so any explanation of your solution will be highly appreciated. Thanks again.

Answer 1

Some recursion should do the trick:

Array.prototype.recursiveIndexOf = function(item, start) {
    var i = this.indexOf(item);
    var r, c;

    start = start || [];

    if(i > -1) {
        return start.concat([i]);
    }

    for(i = 0; i < this.length; i++) {
        c = this[i];

        if(Object.prototype.toString.call(c) === '[object Array]') {
            r = c.recursiveIndexOf(item, start.concat(i));

            if(r !== null) {
                return r;
            }
        }
    }

    return null;
};

Here's a demo.

Answer 2

For a two level array, you could do it like this:

function findMultiArray(array, str) {
    var innerArray;
    for (var i = 0; i < array.length; i++) {
        innerArray = array[i];
        for (var j = 0; j < innerArray.length; j++) {
            if (innerArray[j] == str) {
                return([i, j]);
            }
        }
    } 
    return null;
}

Note, I had it just return an actual array with the two indexes since that's a little easier to use if you need the data in data form.

Unlike in your request, it will never return the equivalent of a[1] because a[1] is an array, not a string so the match is with a[1][0] , not with a[1] . In that case, it would return [1,0] .

If you want the return value in a different form, there's just one line of code where is sees the match and i and j are the indexes that matched.

If the level of arrays can be arbitrarily deep with different depths in different places, then that would be a little more involved and would require interrogating the type of items to see if they contained nested arrays or just strings and would require some sort of stack to maintain the current position. It would be easiest to do with recursion.

Answer 3

Here is a much simpler answer. ;)

function array_search(ob,str)
{
    for(var i=0;i<ob.length;++i)
    {
        if(typeof(ob[i])=='object'&&(ob[i] instanceof Array))
        {
            var foo=array_search(ob[i],str);
            if(foo!=null)
                return i+'->'+foo;
        }else
        if(typeof(ob[i])=='string'&&ob[i]==str)
        {
            return i;
        }
    }
    return null;
}

var a = ["Once upon a time there was a man."];
a[1] = ["He was tall."];
a[1][1] = ["He often bumped his head."];
a[2] = ["He was short."];
a[2][1] = ["He couldn't reach high shelves."]

alert(array_search(a,'He was short.'));