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:

• Option A: Uses the equals() method, which is the correct way to compare the content of String objects in Java, as it checks if the two strings have the same character sequence.
• Option B: The == operator compares object references, not string content. It will only return true if both variables point to the exact same String object, not just identical text, so it fails for most cases.
• Option C: This is a method call to remove an element, not a boolean expression required for an if condition, so it is invalid syntax here.
• Option D: nameList is an ArrayList, not an array, so the square bracket syntax [] cannot be used to access elements. Additionally, it uses == which has the same issue as Option B.

Answer:

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