Array length property in Java - Cheat Sheet & Quick Revision

overview

Recall & Review

beginner

What does the length property of an array represent in Java?

The length property gives the total number of elements that the array can hold. It tells you how big the array is.

beginner

How do you access the length of an array named numbers in Java?

You use numbers.length to get the number of elements in the array.

beginner

True or False: In Java, length is a method for arrays.

False. In Java, length is a property (field) of arrays, not a method. So you do not use parentheses.

intermediate

What happens if you try to access an index equal to or greater than array.length?

You get an ArrayIndexOutOfBoundsException error because array indexes start at 0 and go up to length - 1.

intermediate

Can the length of an array be changed after the array is created in Java?

No. The length of an array is fixed once the array is created. To change size, you need to create a new array.

How do you get the number of elements in a Java array named arr?

A length(arr)

B arr.length()

C arr.size()

D arr.length

What is the index of the last element in an array with length 10?

A 9

B 10

C 0

D 11

If you try to access arr[arr.length], what happens?

A Throws ArrayIndexOutOfBoundsException

B Returns null

C Returns the last element

D Returns the first element

Can you change the size of an existing array in Java?

A Yes, by setting a new length

B Yes, using <code>resize()</code> method

C No, arrays have fixed length

D Yes, by assigning a new value to <code>length</code>

Which of these is correct to get the length of a Java array?

A array.length()

B array.length

C array.getLength()

D array.size

Explain how to find the number of elements in a Java array and why the length property is important.

Describe what happens if you try to access an array index outside the valid range using the length property.