With method overloading, multiple methods can have the same name with different parameters:
int myMethod(int x)
float myMethod(float x)
double myMethod(double x, double y)Consider the following example, which has two methods that add numbers of different type: Continue reading Java Method Overloading
In the previous page, we used the void keyword in all examples, which indicates that the method should not return a value.
If you want the method to return a value, you can use a primitive data type (such as int, char, etc.) instead of void, and use the return keyword inside the method: Continue reading Java Return
Information can be passed to methods as a parameter. Parameters act as variables inside the method.
Parameters are specified after the method name, inside the parentheses. You can add as many parameters as you want, just separate them with a comma.
The following example has a method that takes a String called fname as parameter. When the method is called, we pass along a first name, which is used inside the method to print the full name: Continue reading Java Method Parameters
A method is a block of code which only runs when it is called.
You can pass data, known as parameters, into a method.
Methods are used to perform certain actions, and they are also known as functions.
Why use methods? To reuse code: define the code once, and use it many times.
A multidimensional array is an array of arrays.
Multidimensional arrays are useful when you want to store data as a tabular form, like a table with rows and columns.
To create a two-dimensional array, add each array within its own set of curly braces:
int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
myNumbers is now an array with two arrays as its elements.
To demonstrate a practical example of using arrays, let’s create a program that calculates the average of different ages:
// An array storing different ages
int ages[] = {20, 22, 18, 35, 48, 26, 87, 70};
float avg, sum = 0;
// Get the length of the array
int length = ages.length;
// Loop through the elements of the array
for (int age : ages) {
sum += age;
}
// Calculate the average by dividing the sum by the length
avg = sum / length;
// Print the average
System.out.println("The average age is: " + avg);
And in this example, we create a program that finds the lowest age among different ages: Continue reading Java Arrays Examples
You can loop through the array elements with the for loop, and use the length property to specify how many times the loop should run.
The following example outputs all elements in the cars array:
String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
for (int i = 0; i < cars.length; i++) {
System.out.println(cars[i]);
}
Arrays are used to store multiple values in a single variable, instead of declaring separate variables for each value.
To declare an array, define the variable type with square brackets:
String[] cars;
We have now declared a variable that holds an array of strings. To insert values to it, you can place the values in a comma-separated list, inside curly braces:
String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
To create an array of integers, you could write:
int[] myNum = {10, 20, 30, 40};
You have already seen the break statement used in an earlier chapter of this tutorial. It was used to “jump out” of a switch statement.
The break statement can also be used to jump out of a loop.
This example stops the loop when i is equal to 4:
for (int i = 0; i < 10; i++) {
if (i == 4) {
break;
}
System.out.println(i);
}
To demonstrate a practical example of the for loop, let’s create a program that counts to 100 by tens:
for (int i = 0; i <= 100; i += 10) {
System.out.println(i);
}
In this example, we create a program that only print even values between 0 and 10: Continue reading Java For Loop Examples