checkIndex Java

In Java programming language, checkIndex is a method that checks if an index is within a specified range. This method is useful when dealing with arrays, strings or any other data structure that has an index. The method is part of the Guava library developed by Google and is often used in conjunction with the Preconditions class to ensure that an input parameter meets certain conditions before it is passed to a function.

Syntax

The syntax of the checkIndex method is as follows:

checkIndex(int index, int length)

where index is the index to check and length is the length of the data structure being indexed.

Functionality

The checkIndex method throws an IndexOutOfBoundsException if the specified index is negative or greater than or equal to the length of the data structure being indexed. It does nothing if the index is valid.

Here is an example of using the checkIndex method:

import com.google.common.base.Preconditions;
//...
int[] array = {1, 2, 3, 4, 5};
int index = 6;

try {
    Preconditions.checkIndex(index, array.length);
    // do something with array[index]
} catch (IndexOutOfBoundsException e) {
    System.out.println("Index out of bounds!");
}

In this example, checkIndex is used to ensure that the index variable is within the valid range of the array data structure. If the index is out of bounds, an IndexOutOfBoundsException is thrown and caught by the catch block.

Conclusion

The checkIndex method is a useful tool for ensuring that an index value is within a valid range. It can help to prevent errors in your code and ensure that your program behaves as expected. If you are working with arrays or other indexed data structures, consider using the checkIndex method to verify your inputs.