Question

consider the following method that is intended to modify its parameter namelist by replacing all occurrences of name with newvalue.
public void replace(arraylist<string> namelist, string name, string newvalue)
{
for (int j = 0; j < namelist.size(); j++)
{
if ( / expression / )
{
namelist.set(j, newvalue);
}
}
}
which of the following can be used to replace / expression / so that replace will work as intended?
a.
namelist.get(j).equals(name)
b.
namelist.get(j) == name
c.
namelist.remove(j)
d.
namelistj == name

Explanation:

To determine the correct expression, we analyze each option:

• Option A: In Java, to compare the content of two String objects, we use the equals() method. nameList.get(j).equals(name) checks if the element at index j in nameList has the same content as the name string. This is the correct way to check for equality of String values.
• Option B: The == operator for String objects in Java checks for reference equality (whether they refer to the same object in memory), not content equality. So this is incorrect.
• Option C: nameList.remove(j) is an operation to remove an element, not a boolean expression to check for equality. So this is incorrect.
• Option D: nameList is an ArrayList, and we cannot use the array indexing syntax ([]) with an ArrayList. Also, as mentioned before, == is not the right way to compare String content. So this is incorrect.

Answer:

A. nameList.get(j).equals(name)