Quora
quora.com › What-is-the-difference-between-length-and-size-in-Java
What is the difference between length and size in Java? - Quora
Answer (1 of 4): * In java size ... is contain by collection (not the capacity). * where as .length is a field which works with arrays and gives capacity of arrays. * also length is a m......
Reddit
reddit.com › r/learnprogramming › [java] size vs. length
r/learnprogramming on Reddit: [Java] size vs. length
July 16, 2013 -
What is the reasoning behind why some objects use size() and some use length(). Why don't they all use one or the other?
Top answer 1 of 3
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Arrays are fixed length so they use a field/variable that gets set on initialization. Lists are variable length so they need a method to figure out their own size.
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I think it's only arrays that use length (not length()). Everything else that I can think of uses "size()". Arrays are weird. They are objects, but they are implemented directly in the language and not via a library. The have members (like clone() and length), but you can't access them via reflection. Personally, I think the authors of Java just made a mistake. They probably should have made it be size(), for consistency with the other containers. I'm not sure if there is a good reason why they didn't. It's just something you have to get used to.
java - Difference between size and length methods? - Stack Overflow
Is .size() only for arraylists and .length only for arrays? ... This seems programming language specific, and there's no tag. ... The canonical answer: stackoverflow.com/questions/300522/… This one is also good: stackoverflow.com/questions/1965500/length-and-length-in-java More on stackoverflow.com
In Java, why is there no standard method for finding the size/length of different collections?
Is there any reason that there isn't uniformity in syntax here? Screw ups when the language was designed. That's pretty much it. It's something you get used to in no time anyway so it's not that big a deal other than it's slightly annoying that they're not consistent. More on reddit.com
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November 28, 2015[Java] size vs. length
Arrays are fixed length so they use a field/variable that gets set on initialization. Lists are variable length so they need a method to figure out their own size. More on reddit.com
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July 16, 2013Why is it String.length() instead of String.getLength()? How to name my own length method?
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September 13, 2023GeeksforGeeks
geeksforgeeks.org › java › difference-between-length-of-array-and-size-of-arraylist-in-java
Difference between length of Array and size of ArrayList in Java - GeeksforGeeks
July 11, 2025 - Array has length property which provides the length of the Array or Array object. It is the total space allocated in memory during the initialization of the array. Array is static so when we create an array of size n then n blocks are created ...
TutorialsPoint
tutorialspoint.com › how-to-determine-length-or-size-of-an-array-in-java
How to determine length or size of an Array in Java?
July 19, 2023 - In Java, one of the convenient ways to determine the length or size of an array is by using its length property. It counts the number of elements stored in an array and returns the count. Finding the length of an array is one of the common yet crucial operation as it is used to find the number ...
TheServerSide
theserverside.com › blog › Coffee-Talk-Java-News-Stories-and-Opinions › Java-array-size-explained-by-example
Java array size, length and loop examples
However, Java arrays do not have a size() method, nor do they have a length() method. Instead, the property length provides a Java array’s size. To further confuse matters, every Java collection class that implements the List interface does have a size() method. Classes including Vector, Stack and ArrayList all have a size method.
Pluralsight
pluralsight.com › tech insights & how-to guides › software development
How to initialize an array in Java | Pluralsight
Note that for the above to work, each sub-array needs to be of the same length. An array’s size is fixed, and can’t change after being initialized. However, you can work around this by initializing a new array of a different size, and simply copying the old values over.
W3Schools
w3schools.com › java › java_data_types.asp
Java Data Types
Java Wrapper Classes Java Generics Java Annotations Java RegEx Java Threads Java Lambda Java Advanced Sorting ... How Tos Add Two Numbers Swap Two Variables Even or Odd Number Reverse a Number Positive or Negative Square Root Area of Rectangle Celsius to Fahrenheit Sum of Digits Check Armstrong Num Random Number Count Words Count Vowels in a String Remove Vowels Count Digits in a String Reverse a String Palindrome Check Check Anagram Convert String to Array Remove Whitespace Count Character Frequency Sum of Array Elements Find Array Average Sort an Array Find Smallest Element Find Largest Element Second Largest Array Min and Max Array Merge Two Arrays Remove Duplicates Find Duplicates Shuffle an Array Factorial of a Number Fibonacci Sequence Find GCD Check Prime Number ArrayList Loop HashMap Loop Loop Through an Enum
Educative
educative.io › answers › how-to-find-the-length-of-a-string-in-java
How to find the length of a string in Java
To calculate the length of a string in Java, you can use an inbuilt length() method of the Java string class. In Java, strings are objects created using the string class and the length() method is apublic member method of this class.
Codecademy
codecademy.com › docs › java › arrays › .length
Java | Arrays | .length | Codecademy
April 21, 2025 - In Java, the .length property is used to determine the length or size of an array. It is a built-in property for arrays and returns an integer value that represents the number of elements in the array.
W3Schools
w3schools.com › java › ref_arrays_length.asp
Java Array length Property
The length property returns the length of an array. This is a built-in Java property, and does not belong to the Java Arrays Class.
HappyCoders.eu
happycoders.eu › java › array-length-in-java
Array Length in Java
June 12, 2025 - The length of an array is defined when it is initialized. The following code, for example, creates a string array of size four: String[] fruits = {"jujube", "apple", "boysenberry", "cherry"};Code language: Java (java)
Top answer 1 of 7
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size() is a method specified in java.util.Collection, which is then inherited by every data structure in the standard library. length is a field on any array (arrays are objects, you just don't see the class normally), and length() is a method on java.lang.String, which is just a thin wrapper on a char[] anyway.
Perhaps by design, Strings are immutable, and all of the top-level Collection subclasses are mutable. So where you see "length" you know that's constant, and where you see "size" it isn't.
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length is constant which is used to find out the array storing capacity not the number of elements in the array
Example:
int[] a = new int[5]
a.length always returns 5, which is called the capacity of an array. But
number of elements in the array is called size
Example:
int[] a = new int[5]
a[0] = 10
Here the size would be 1, but a.length is still 5. Mind that there is no actual property or method called size on an array so you can't just call a.size or a.size() to get the value 1.
The size() method is available for collections, length works with arrays in Java.
Baeldung
baeldung.com › home › java › java string › java’s string.length() and string.getbytes().length
Java’s String.length() and String.getBytes().length | Baeldung
July 6, 2024 - But these can also be overused and fall into some common pitfalls. To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:
GeeksforGeeks
geeksforgeeks.org › java › how-to-find-length-or-size-of-an-array-in-java
How to Find Length or Size of an Array in Java? - GeeksforGeeks
The length property is the most common way to find the size of an array in Java.
Published July 12, 2025
Baeldung
baeldung.com › home › java › java io › file size in java
File Size in Java | Baeldung
November 29, 2023 - In this quick tutorial, we’ll ... a file in Java – using Java 7, the new Java 8 and Apache Common IO. Finally – we will also get a human readable representation of the file size. Let’s start with a simple example of calculating the size of a file – using the File.length() ...
Interview Kickstart
interviewkickstart.com › home › blogs › learn › length vs. length method in java
Length vs. Length Method in Java | Interview Kickstart
December 18, 2025 - You can use this length attribute or variable to find the size of an array in Java by using the dot operator with the array name. For example, Array.length will give you the length of the array named “Array.” · length() in Java is a final ...
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JanBask Training
janbasktraining.com › community › java › arraysize-vs-arraylength
Array.size() vs Array.length | JanBask Training Community
August 24, 2025 - Array.size() (or simply .size) ... as both are interchangeable. ... In Java, you’ll always use .length for arrays and .size() for collections like ArrayList....
Baeldung
baeldung.com › home › persistence › jpa › difference between @size, @length, and @column(length=value)
Difference Between @Size, @Length, and @Column | Baeldung
2 weeks ago - Simply put, all of these annotations are meant to communicate the size of a field. @Size and @Length are similar. We can use either annotation to validate the size of a field. The former is a Java...
Coding Rooms
codingrooms.com › blog › 2d-array-length-java
2D Array Length Java
We use arrayname.length to determine the number of rows in a 2D array because the length of a 2D array is equal to the number of rows it has.
Software Testing Help
softwaretestinghelp.com › home › java tutorial for beginners: 100+ hands-on java video tutorials › java array length tutorial with code examples
Java Array Length Tutorial With Code Examples
April 1, 2025 - Answer: The length property of an array gives the size of the array or the total number of elements present in the array. There is no length property in the ArrayList but the number of objects or elements in the ArrayList is given by size () method.