Object-oriented programming languages are popular among software engineers preparing for coding interviews; among them, Java is one of the most widely used languages by software developers. While preparing for tech interviews at FAANG and other tier-1 tech companies, it is important to brush up on your basics. In this article, we will discuss the difference between the length attribute and the length() method in Java.

Here’s what we’ll cover:

1. What is the length variable in Java?
2. What is the length() method in Java?
3. Difference between length and length()
4. Example problems on the length and length() in Java

What Is the “length” Variable in Java?

In Java, the number of elements an array can hold, or the size of the array, is called its length. 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.”

What Is the “length()” Method in Java?

length() in Java is a final method, which is applicable for string objects. You can use it to find the number of characters in a string.

For example, string.length() will return the number of characters in “string.”

Differences Between “length” and “length()” in Java

Here’s a summary of the key differences between length and length():

Code Example:

public class IK{

    public static void main(String[] args)

    {

        // a is an integer array of size 10-

        int[] a= new int[10];

        System.out.println("Size of an array a is "+ a.length);

        // Variable Str is a String object.

        String Str= "InterviewKickstart";

        System.out.println("Size of the String is "+ Str.length());

    }

}

Output

Size of an array a is 10

Size of the String is 18

Problems on length vs. length() in Java

Q. What will be the output of the following code?

Code 1: 

public class IK{

    public static void main(String[] args)

    {

        String[] S= { "ONE", "TWO", "THREE", "FOUR" };

        System.out.println(S.length);

    }

}

Output: 4

Explanation: In the above code, the variable “S” is an array of type strings. So, S.length can be used to get the length of the given array. Hence, the output is 4.

Code 2:

public class IK{

    public static void main(String[] args)

    {

        String[] S= { "ONE", "TWO", "THREE", "FOUR" };

        System.out.println(S.length());

    }

}

Output: 

error: cannot find symbol

symbol: method length()

location: variable S of type String[]

Explanation: Method length() is defined for Strings. In the above code, variable S is an array of type string, and thus method length() can not be used on it. 

Code 3:

public class IK{

    public static void main(String[] args)

    {

        String[] S= { "ONE", "TWO", "THREE", "FOUR" };

        System.out.println(S[0].length());

    }

}

Output: 3

Explanation: In the above code, S[0] is a String object; it has stored the string "ONE," and hence the length() method can be used on it to get its length.

Recommended Reading

1. Split() String Method in Java
2. How to Reverse a String in Java
3. Overriding in Java
4. Collections Sort in Java

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Article contributed Omkar Deshmukh