JAVA
Lesson 3: Functions
Function
What is a Fuction? Organize and group code Perform a specific task
- Function definition
- Contains the code a finction executes
- Calling a function is equivalent to execution the cide in the definition
public void chorus() {
if(playButton){
}
else{
}
}
- public : access modigier
- void : return type
-
function name : how ew call our function ex)chorus is function name at that code
- Function Calling
public void chorus() {
if(x= null)
}
chorus(); //call a function
- Parameters and Arguments
public void greeting(String location){ //Argument : location)
System.out.println("Hello, " + location);
}
greeting(Korea); // print out : Hello Korea
public void weatherInterpreter(int temperature) {
if (temperature > 30) {
System.out.println("It's hot outside!");
} else if (temperature < 5){
System.out.println("Brr, consider wearing a jacket.");
} else {
System.out.println("Not too hot, not too cold.");
}
}
weatherInterpreter(4); // print out : Brr, consider wearing a jacket.
weatherInterpreter(32); //print out : It's hot outside!
int degreesC = 15;
weatherInterpreter(degreesC); //print out : Not too hot, not too cold.
Return Values
public double makeChange(double itemCost, double dollarsProvided) {
double change = dollarsProvided - itemCost;
return change;
}
Random Numbers
//random num between 0 and (almost) 1
double randomNumber = Math.random();
// change range to 0 to (almost) 10
randomNumber = randomNumber * 10;
// casting : cast to integer (ignore decimal part)
// ex. 9.985 becomes 9
int randomInt = (int) randomNumber
- Random dice
public int rollDice(int sides){
// random num between 0 and (almost) 1
double randomNumber=Math.random();
// change range to 0 to (almost) 6
randomNumber=randomNumber*sides;
// shift range up one
randomNumber=randomNumber+1;
// cast to integer (ignore decimal part)
// ex. 6.998 becomes 6
int randomInt=(int)randomNumber;
// return statement
return randomInt;
}
I’m studing a “Java Programming Basics” @Udacity.