Comparing array value with object

Would be really grateful for any help. Im pretty new to javascript and cant figure out how to solve this problem that I am having. Basically I have 2 arrays. One contains an object with an id value and a corresponding group value. The second array contains only the id. I would like to compare the ids of both the arrays and if they match I would like to extract the corresponding group value.

E.g.

a = [1,2,3,4,5];

b = [{1:group1},{2:group2},{3:group3}];

If id in a matches id in b then print out the id's group value

var a = [];
var b = [];
var c = {};


if (condition) {
   c  = {id:group}
   b.push(c)

}

if (condition) {
   a.push(id)

}

for (var i = 0; i < a.length; i++) {
   //If id value in a exists in b, get id's corresponding group value from b
}