Optimize Javascript data Traversal

Optimize Javascript data Traversal
Problem

M is a collection of objects. No object has a unique string type Id.

N is the set of IDs.

Filter out objects whose IDs are not in N from M.

If M has 50 W data records, N may be 0 ~ Arbitrary data.

Solution 1

Use an array to save the set of IDs.

In this way, there are two ways to traverse

1.1

N = [id,...];

For (var m in M)

For (var n in N ){

.....

}

1.2

For (var m in M)

If (N. indexOf (m. id)>-1 ){

}

Solution 2

Use "dict/map" to save the set of IDS

N = {id: 0 },....};

2.1

// Traverse

For (var m in M)

If (n [m. id]! = Undefined ){

....

}

Conclusion

Dict and array PK. The result is obvious. The speed is 2.1> 1.2> 1.1.