Class notes | Methods | Intro to Computer Programming (COMP150) Introduction to Java Programming and Data Structures, ISBN: 9780134670942

Methods
Date @October 7, 2022

Introduction to Java Programming and Data Structures, Comprehensive
Text Version: Chapter 6


Defining Methods
A method is a collection of statements that are grouped together to perform an
operation


// define the method
public static int max(int num1, int num2) {
int result;
if (num1>num2) {
result = num1;
} else {
result = num2
}
return result;
}

// invoke the method
int z = max(x, y);




public static int max(int num1, int num2) - method header

public static - modifier
int - returnValueType

the data type of the value that is returned by the method

if the method does not return a value, the returnValueType is the keyword void

max - method name
(int num1, int num2) - method signature

combination of the method name and the parameter list

int num1, int num2 - parameter list



Methods 1

, num1 & num2 - formal parameters

variables defined in the method header

return result; - return value
x & y - actual parameters (arguments)

the value passed on to the parameter when a method is invoked

Calling Methods

// define the method
public static int max(int num1, int num2) {
int result;
if (num1>num2) {
result = num1;
} else {
result = num2
}
return result;
}

public static void main (String[] args) {
int i = 5;
int j = 2;
int k = max(i, j)

System.out.println("The maximum between " + i + " and " + j + " is " + k);
}




this program takes the integer values of i and j and puts them through the max

method,


caution:


// section a
public static int sign(int n) {
if (n > 0) {
return 1;
} else if (n == 0) {
return 0;
} else if (n < 0) {
return -1;
}
}




Methods 2