Java Array

Java Regex

Java RMI

Java Long class

next → ← prev

Java String length()

The Java String class length() method finds the length of a string. The length of the Java string is the same as the Unicode code units of the string.

Signature

The signature of the string length() method is given below:

Specified by

CharSequence interface

Returns

Length of characters. In other words, the total number of characters present in the string.

Internal implementation

  public int length() {
        return value.length;
    }

The String class internally uses a char[] array to store the characters. The length variable of the array is used to find the total number of elements present in the array. Since the Java String class uses this char[] array internally; therefore, the length variable can not be exposed to the outside world. Hence, the Java developers created the length() method, the exposes the value of the length variable. One can also think of the length() method as the getter() method, that provides a value of the class field to the user. The internal implementation clearly depicts that the length() method returns the value of then the length variable.

Java String length() method example

FileName: LengthExample.java

public class LengthExample{
public static void main(String args[]){
String s1="javatpoint";
String s2="python";
System.out.println("string length is: "+s1.length());//10 is the length of javatpoint string
System.out.println("string length is: "+s2.length());//6 is the length of python string
}}

Output:

string length is: 10
string length is: 6

Java String length() Method Example 2

Since the length() method gives the total number of characters present in the string; therefore, one can also check whether the given string is empty or not.

FileName: LengthExample2.java

public class LengthExample2 {
	public static void main(String[] args) {
		String str = "Javatpoint";
		if(str.length()>0) {
			System.out.println("String is not empty and length is: "+str.length());
		}
		str = "";
		if(str.length()==0) {
			System.out.println("String is empty now: "+str.length());
		}
	}
}

Output:

String is not empty and length is: 10
String is empty now: 0

Java String length() Method Example 3

The length() method is also used to reverse the string.

FileName: LengthExample3.java

class LengthExample3 
{
// main method
public static void main(String argvs[])
{
String str = "Welcome To JavaTpoint";
int size = str.length();

System.out.println("Reverse of the string: " + "'" + str + "'" + " is");

for(int i = 0; i < size; i++)
{
// printing in reverse order
System.out.print(str.charAt(str.length() - i - 1));
}

}
}

Output:

Reverse of the string: 'Welcome To JavaTpoint' is
tniopTavaJ oT emocleW

Java String length() Method Example 4

The length() method can also be used to find only the white spaces present in the string. Observe the following example.

FileName: LengthExample4.java

public class LengthExample4
{
// main method
public static void main(String argvs[])
{
String str = " Welcome To JavaTpoint ";
int sizeWithWhiteSpaces = str.length();

System.out.println("In the string: " + "'" + str + "'");

str = str.replace(" ", "");
int sizeWithoutWhiteSpaces = str.length();

// calculating the white spaces
int noOfWhieSpaces = sizeWithWhiteSpaces - sizeWithoutWhiteSpaces;

System.out.print("Total number of whitespaces present are: " + noOfWhieSpaces);
}
}

Output:

In the string: ' Welcome To JavaTpoint '
Total number of whitespaces present are: 4

Next TopicJava String replace()

← prev next →

Latest Courses

Data-Structures

Cloud-Computing

Ethical-Hacking

We provides tutorials and interview questions of all technology like java tutorial, android, java frameworks

Contact info

G-13, 2nd Floor, Sec-3, Noida, UP, 201301, India

[email protected].

Follow us

Tutorials

Java Data Structures C Programming C++ Tutorial C# Tutorial PHP Tutorial HTML Tutorial JavaScript Tutorial jQuery Tutorial Spring Tutorial

Interview Questions

Tcs Intuit Wipro Adobe Infosys Amazon Accenture Cognizant Capgemini Microsoft

Online Compiler

C R C++ Php Java Html Swift Python JavaScript TypeScript

© Copyright 2024 Javatpoint. All Rights Reserved.