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 for the if condition in the replace method, we analyze each option:

• Option A: In Java, to compare the content of two String objects, we use the equals() method (since == compares object references, not content). nameList.get(j).equals(name) checks if the String at index j in nameList has the same content as the name parameter. This is correct for replacing all occurrences of name with newValue.

• Option B: The == operator compares object references (memory addresses) for String objects, not their content. So nameList.get(j) == name will not reliably check if the String values are equal.

• Option C: nameList.remove(j) is a method to delete an element, not a boolean expression for comparison. It does not check if the element matches name, so it is invalid here.

• Option D: nameList[j] is invalid syntax for an ArrayList in Java (arrays use [], but ArrayList uses methods like get()/set()). Additionally, == is still incorrect for String content comparison.

Answer:

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