Using the merge method of the Map interface, which statement correctly updates the salesTotalByDept map of type Map to update the sales total for a dept by an integer sales value? A)salesTotalByDept.merge(dept, sales,(d,s) - s + 1); B)sales.merge(salesTotalByDept, dept, (d,s) - s + sales); C)dept.merge(salesTotalByDept, sales, (d,s) - s + sales); D)salesTotalByDept.merge(dept, sales, (d,s) - s + sales);

Question

Using the merge method of the Map interface, which statement correctly updates the salesTotalByDept map of type Map<String,Integer> to update the sales total for a dept by an integer sales value?
A)salesTotalByDept.merge(dept, sales,(d,s) -> s + 1);
B)sales.merge(salesTotalByDept, dept, (d,s) -> s + sales);
C)dept.merge(salesTotalByDept, sales, (d,s) -> s + sales);
D)salesTotalByDept.merge(dept, sales, (d,s) -> s + sales);

Quizplus · Accepted Answer

Option A is incorrect because it will always add 1 instead of the actual sales value.

Option B is incorrect because the order of the parameters is wrong.

Option C is incorrect because the merge method should be called on the salesTotalByDept map, not on the dept map.

Option D is the correct choice as it updates the sales total for a department by adding the existing value for the department and the new sales value together.

Using the Merge Method of the Map Interface, Which Statement