比较JavaScript中的两个数组

Question

I'd like to check which elements are equal in my two arrays, but can't get it working.
This is my code:

for (var i; i < bombs.length; i++) {
    for (var j; j < bombsDb.length; j++) {
        if (bombs[i].name === bombsDb[j].address) {
            console.log(bombs[i].name);
        } else {
            console.log("non-equal elements");
        }
    }
}

So the first array contains objects from the google places api and the second one contains data from my database.
Thanks in advance!

Answer 1

You have to initialize i and j ;

   for (var i = 0; i < bombs.length; i++) {
        for (var j = 0; j < bombsDb.length; j++) {
            if (bombs[i].name === bombsDb[j].address) {
                console.log(bombs[i].name);
            } else {
                console.log("non-equal elements");
            }
        }
    }

Answer 2

Comparing can also be done using the .not selector from jquery. Check this:

var a = [1,2,3,4,5,6];
var b = [4,5,6,7,8,9];

$(a).not( $(a).not(b).get() ).get(); 

This will return the following array

[4,5,6]

Answer 3

You are missing the initial assignment to i and j in your for loop.

//          here
//           v
for (var i = 0; i < bombs.length; i++) {
    // your loop
}

This causes the comparision to return false in the first iteration of the loop since undefined < bombs.length always return false, so it will not proceed.