Dividing a complex problem into smaller chunks makes your program easy to understand and reusable.<\/p>\n\n\n\n
In Java, there are two types of methods:<\/p>\n\n\n\n
- User-defined Methods<\/strong>: We can create our own method based on our requirements.<\/li>
- Standard Library Methods<\/strong>: These are built-in methods in Java that are available to use.<\/li><\/ul>\n\n\n\n
Let’s first learn about user-defined methods.<\/p>\n\n\n\n
\n\n\n\nDeclaring a Java Method<\/h2>\n\n\n\n
The syntax to declare a method is:<\/p>\n\n\n\n
returnType methodName() {\n \/\/ method body\n}<\/code><\/pre>\n\n\n\nHere,<\/p>\n\n\n\n
- returnType<\/strong>\u00a0– It specifies what type of value a method returns For example if a method has an\u00a0
int<\/code>\u00a0return type then it returns an integer value.
If the method does not return a value, its return type is\u00a0void<\/code>.<\/li>- methodName<\/strong>\u00a0– It is an\u00a0identifier\u00a0that is used to refer to the particular method in a program.<\/li>
- method body<\/strong>\u00a0– It includes the programming statements that are used to perform some tasks. The method body is enclosed inside the curly braces\u00a0
{ }<\/code>.<\/li><\/ul>\n\n\n\nFor example,<\/p>\n\n\n\n
int addNumbers() {\n\/\/ code\n}<\/code><\/pre>\n\n\n\nIn the above example, the name of the method is
adddNumbers()<\/code>. And, the return type isint<\/code>. We will learn more about return types later in this tutorial.<\/p>\n\n\n\nThis is the simple syntax of declaring a method. However, the complete syntax of declaring a method is<\/p>\n\n\n\n
modifier static returnType nameOfMethod (parameter1, parameter2, ...) {\n \/\/ method body\n}<\/code><\/pre>\n\n\n\nHere,<\/p>\n\n\n\n
- modifier<\/strong>\u00a0– It defines access types whether the method is public, private, and so on. To learn more, visit\u00a0Java Access Specifier.<\/li>
- static<\/strong>\u00a0– If we use the\u00a0
static<\/code>\u00a0keyword, it can be accessed without creating objects.
For example, the\u00a0sqrt()<\/code>\u00a0method of standard\u00a0Math class\u00a0is static. Hence, we can directly call\u00a0Math.sqrt()<\/code>\u00a0without creating an instance of\u00a0Math<\/code>\u00a0class.<\/li>- parameter1\/parameter2<\/strong>\u00a0– These are values passed to a method. We can pass any number of arguments to a method.<\/li><\/ul>\n\n\n\n
\n\n\n\nCalling a Method in Java<\/h2>\n\n\n\n
In the above example, we have declared a method named
addNumbers()<\/code>. Now, to use the method, we need to call it.<\/p>\n\n\n\nHere’s is how we can call the
addNumbers()<\/code> method.<\/p>\n\n\n\n\/\/ calls the method\naddNumbers();<\/code><\/pre>\n\n\n\n![\"Call](\"https:\/\/cdn.programiz.com\/sites\/tutorial2program\/files\/java-method-call.png\" "\\"Working")
Working of Java Method Call<\/figcaption><\/figure>\n\n\n\n
\n\n\n\nExample 1: Java Methods<\/h2>\n\n\n\n
class Main {\n\n \/\/ create a method\n public int addNumbers(int a, int b) {\n int sum = a + b;\n \/\/ return value\n return sum;\n }\n\n public static void main(String[] args) {\n \n int num1 = 25;\n int num2 = 15;\n\n \/\/ create an object of Main\n Main obj = new Main();\n \/\/ calling method\n int result = obj.addNumbers(num1, num2);\n System.out.println(\"Sum is: \" + result);\n }\n}<\/code><\/pre>\n\n\n\nOutput<\/strong><\/p>\n\n\n\n
Sum is: 40<\/samp><\/code><\/pre>\n\n\n\nIn the above example, we have created a method named
addNumbers()<\/code>. The method takes two parameters a<\/var> and b<\/var>. Notice the line,<\/p>\n\n\n\nint result = obj.addNumbers(num1, num2);<\/code><\/pre>\n\n\n\nHere, we have called the method by passing two arguments num1<\/var> and num2<\/var>. Since the method is returning some value, we have stored the value in the result<\/var> variable.<\/p>\n\n\n\n
Note<\/strong>: The method is not static. Hence, we are calling the method using the object of the class.<\/p>\n\n\n\n
\n\n\n\nJava Method Return Type<\/h2>\n\n\n\n
A Java method may or may not return a value to the function call. We use the return statement<\/strong> to return any value. For example,<\/p>\n\n\n\n
int addNumbers() {\n...\nreturn sum;\n}<\/code><\/pre>\n\n\n\nHere, we are returning the variable sum<\/var>. Since the return type of the function is
int<\/code>. The sum variable should be ofint<\/code> type. Otherwise, it will generate an error.<\/p>\n\n\n\nExample 2: Method Return Type<\/h3>\n\n\n\n
class Main {\n\n\/\/ create a method\n public static int square(int num) {\n\n \/\/ return statement\n return num * num;\n }\n\n public static void main(String[] args) {\n int result;\n\n \/\/ call the method\n \/\/ store returned value to result\n result = square(10);\n\n System.out.println(\"Squared value of 10 is: \" + result);\n }\n}<\/code><\/pre>\n\n\n\nOutput<\/strong>:<\/p>\n\n\n\n
Squared value of 10 is: 100<\/samp><\/code><\/pre>\n\n\n\nIn the above program, we have created a method named
square()<\/code>. The method takes a number as its parameter and returns the square of the number.<\/p>\n\n\n\nHere, we have mentioned the return type of the method as
int<\/code>. Hence, the method should always return an integer value.<\/p>\n\n\n\n![\"Java](\"https:\/\/cdn.programiz.com\/sites\/tutorial2program\/files\/java-method-return-value.png\" "\\"Representation")
Representation of the Java method returning a value<\/figcaption><\/figure>\n\n\n\n Note<\/strong>: If the method does not return any value, we use the void keyword as the return type of the method. For example,<\/p>\n\n\n\n
public void square(int a) {\n int square = a * a;\n System.out.println(\"Square is: \" + a);\n}<\/code><\/pre>\n\n\n\n
\n\n\n\nMethod Parameters in Java<\/h2>\n\n\n\n
A method parameter is a value accepted by the method. As mentioned earlier, a method can also have any number of parameters. For example,<\/p>\n\n\n\n
\/\/ method with two parameters\nint addNumbers(int a, int b) {\n \/\/ code\n}\n\n\/\/ method with no parameter\nint addNumbers(){\n \/\/ code\n}<\/code><\/pre>\n\n\n\nIf a method is created with parameters, we need to pass the corresponding values while calling the method. For example,<\/p>\n\n\n\n
\/\/ calling the method with two parameters\naddNumbers(25, 15);\n\n\/\/ calling the method with no parameters\naddNumbers()<\/code><\/pre>\n\n\n\n
\n\n\n\nExample 3: Method Parameters<\/h3>\n\n\n\n
class Main {\n\n \/\/ method with no parameter\n public void display1() {\n System.out.println(\"Method without parameter\");\n }\n\n \/\/ method with single parameter\n public void display2(int a) {\n System.out.println(\"Method with a single parameter: \" + a);\n }\n\n public static void main(String[] args) {\n \n \/\/ create an object of Main\n Main obj = new Main();\n\n \/\/ calling method with no parameter\n obj.display1();\n \n \/\/ calling method with the single parameter\n obj.display2(24);\n }\n}<\/code><\/pre>\n\n\n\nOutput<\/strong><\/p>\n\n\n\n
Method without parameter\nMethod with a single parameter: 24<\/samp><\/code><\/pre>\n\n\n\nHere, the parameter of the method is
int<\/code>. Hence, if we pass any other data type instead ofint<\/code>, the compiler will throw an error. It is because Java is a strongly typed language.<\/p>\n\n\n\nNote<\/strong>: The argument 24<\/var> passed to the
display2()<\/code> method during the method call is called the actual argument.<\/p>\n\n\n\nThe parameter num<\/var> accepted by the method definition is known as a formal argument. We need to specify the type of formal arguments. And, the type of actual arguments and formal arguments should always match.<\/p>\n\n\n\n
\n\n\n\nStandard Library Methods<\/h2>\n\n\n\n
The standard library methods are built-in methods in Java that are readily available for use. These standard libraries come along with the Java Class Library (JCL) in a Java archive (*.jar) file with JVM and JRE.<\/p>\n\n\n\n
For example,<\/p>\n\n\n\n
print()<\/code> is a method ofjava.io.PrintSteam<\/code>. Theprint(\"...\")<\/code> method prints the string inside quotation marks.<\/li>sqrt()<\/code> is a method ofMath<\/code> class. It returns the square root of a number.<\/li><\/ul>\n\n\n\nHere’s a working example:<\/p>\n\n\n\n
Example 4: Java Standard Library Method<\/h3>\n\n\n\n
public class Main {\n public static void main(String[] args) {\n \n \/\/ using the sqrt() method\n System.out.print(\"Square root of 4 is: \" + Math.sqrt(4));\n }\n}<\/code><\/pre>\n\n\n\nOutput<\/strong>:<\/p>\n\n\n\n
Square root of 4 is: 2.0<\/samp><\/code><\/pre>\n\n\n\n<\/p>\n\n\n\n
\n\n\n\nWhat are the advantages of using methods?<\/h2>\n\n\n\n
1.<\/strong> The main advantage is code reusability<\/strong>. We can write a method once, and use it multiple times. We do not have to rewrite the entire code each time. Think of it as, “write once, reuse multiple times”.<\/p>\n\n\n\n
Example 5: Java Method for Code Reusability<\/h3>\n\n\n\n
public class Main {\n\n \/\/ method defined\n private static int getSquare(int x){\n return x * x;\n }\n\n public static void main(String[] args) {\n for (int i = 1; i <= 5; i++) {\n\n \/\/ method call\n int result = getSquare(i);\n System.out.println(\"Square of \" + i + \" is: \" + result);\n }\n }\n}<\/code><\/pre>\n\n\n\nOutput<\/strong>:<\/p>\n\n\n\n
Square of 1 is: 1\nSquare of 2 is: 4\nSquare of 3 is: 9\nSquare of 4 is: 16\nSquare of 5 is: 25<\/samp><\/code><\/pre>\n\n\n\nIn the above program, we have created the method named
getSquare()<\/code> to calculate the square of a number. Here, the method is used to calculate the square of numbers less than 6<\/strong>.<\/p>\n\n\n\nHence, the same method is used again and again.<\/p>\n\n\n\n
2.<\/strong> Methods make code more readable and easier<\/strong> to debug. Here, the
getSquare()<\/code> method keeps the code to compute the square in a block. Hence, makes it more readable.<\/p>\n","protected":false},"excerpt":{"rendered":"In this tutorial, we will learn about Java methods, how to define methods, and how to use methods in Java programs with the help of examples. Java Methods A method is a block of code that performs a specific task. Suppose you need to create a program to create a circle and color it. You […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[484],"tags":[],"_links":{"self":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1182"}],"collection":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=1182"}],"version-history":[{"count":0,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1182\/revisions"}],"wp:attachment":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=1182"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=1182"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=1182"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- static<\/strong>\u00a0– If we use the\u00a0
- methodName<\/strong>\u00a0– It is an\u00a0identifier\u00a0that is used to refer to the particular method in a program.<\/li>
- Standard Library Methods<\/strong>: These are built-in methods in Java that are available to use.<\/li><\/ul>\n\n\n\n