javascript - 比较javascript中的多维数组

Question

我想比较 2 个“多维”数组(数组嵌套在数组中)。

var old_dataArray=new Array(("id-2", "message", "user"), ("id-1", "message", "user"), ("id-0", "message", "user"));
var new_dataArray=new Array(("id-3", "message", "user"), ("id-2", "message", "user"), ("id-1", "message", "user"));

在这种情况下，我想获取仅包含在“old_dataArray”中而不包含在“new_dataArray”中的数组(“id-3”、“message”、“user”)。

我已尝试使用此处介绍的 array_diff 函数。 http://phpjs.org/functions/array_diff:309但它并没有真正起作用!

Answer 1

据我了解，您想获取 new_dataArray 中不在 old_dataArray 中的所有数组，我假设如果每个数组中的第一个元素(“id-n”元素)相同，那么数组的其余部分。您可以这样做:

// create an array to store our results:
var results = new Array();

// loop through new_dataArray:
outerloop:
for (var i = 0; i < new_dataArray.length; ++i) {

    // loop through old_dataArray to compare the i'th element
    // in new_dataArray with each in old_dataArray:
    for (var j = 0; j < old_dataArray.length; ++j) {

        // check if the ids are the same
        if (new_dataArray[i][0] == old_dataArray[j][0])
            // yes it's there, so move on to the next element of new_dataArray
            continue outerloop;

    }

    // if we get here, continue outerloop; was never called so 
    // this element is not in old_dataArray
    results.push(new_dataArray[i]);

}

// now results contains all arrays that are in new_dataArray 
// but not in old_dataArray

编辑:但是，如果您希望每个数组中的所有元素都相等，而不仅仅是第一个 (id-n) 元素，请使用:

// create an array to store our results:
var results = new Array();

// loop through new_dataArray:
outerloop:
for (var i = 0; i < new_dataArray.length; ++i) {

    // loop through old_dataArray to compare the i'th element
    // in new_dataArray with each in old_dataArray:
    innerloop:
    for (var j = 0; j < old_dataArray.length; ++j) {

        // check if the arrays are the same size:
        if (new_dataArray[i].length != old_dataArray[j].length)
            // no, so they must be different
            continue innerloop;

        // check if the arrays have the same values
        for (var k = 0; k < old_dataArray[j].length; ++k) {

            if (new_dataArray[i][k] != old_dataArray[j][k])
                // the k'th element is different
                continue innerloop;
        }

        // if we get here, then we have found a match, so move on
        continue outerloop;

    }

    // if we get here, continue outerloop; was never called so 
    // this element is not in old_dataArray
    results.push(new_dataArray[i]);

}

// now results contains all arrays that are in new_dataArray 
// but not in old_dataArray