error: variable might not have been initialized Java

The issue:

We got into this issue when we created an array with few default elements. We declared the array but we didn’t initialize the array and we got the following error:

public class StringArrayTest {
        public static void main(String[] args) {
                String[] topicNameArr;
                topicNameArr[0] = "Chemistry";
        }
}

The reason:

We got this issue because we declared the array but we didn’t initialize the array so it can allocate the correct memory storage for the String elements. As it could not allocate the correct memory storage, the attempt of setting the index generated the error.

The solution:

The solution of the above error is to initialize the array when we declare it. So, if we write the following code then it will solve the issue:

public class StringArrayTest {
        public static void main(String[] args) {
                String[] topicNameArr = new String[1];
                topicNameArr[0] = "Chemistry";
        }
}

Another alternative is to declare and initialize in the line like below:

public class StringArrayTest {
        public static void main(String[] args) {
                String[] topicNameArr = {"Chemistry"};
        }
}