The Ternary Operator
Lesson:
Main Points:
- The ternary operator is often referred to as the conditional
operator.
- It provides a way to code simple conditions (if/else) into a single
expression.
- Some companies prohibit its use because they feel that it makes the
resulting code less readable.
- It is a very concise way to code simple conditionals.
Basic Use of the Ternary Operator:
Here's a real simple example of the ternary operator in action:
<![CDATA[
String size = (x > 2) ? "BIG" : "SMALL";
]]>
In this case whatever value is stored in x will be compared to 2. If it is
greater than two size will be assigned "BIG" and otherwise size will be
assigned "SMALL" as its value. Here is the code for a very similar
example:
<![CDATA[
import java.awt.*;
import java.applet.*;
public class tern extends Applet{
String num="";
int x[] = { 2, 22, 11, 8, 14, 15, 2, 9 };
public void init(){
setBackground(Color.yellow);
}
public void paint(Graphics g){
for(int c = 0; c<x.length; c++){
num = ( x[c]%2 == 0 ) ? "EVEN" : "ODD";
g.drawString(""+x[c] + " is " + num, 10, 20 + c*20);
}
}
}
]]>
More Examples of the Ternary Operator In Action:
<![CDATA[
String ouput="";
output = ( a==10 || a == 20 ) ? "TEN or TWENTY" : "NOT 10 or 20";
// uses short-circuit logical OR operator
String output="";
String name="Barney";
output = ( name.equals("Barney") ) ? "Dinosaur" : "Poodle" ;
// uses String.equals function
boolean short = true;
int output = 0;
output = short ? 100 : 200;
//output assigned 100 since short is true
]]>
Assignment:
Write an applet which contains a list of names contained in an array of type
String. Have at least eight names in your list. For each name determine if
it is the name of a DORK or a NERD. At least three people on your list
should be DORKs and at least three people on your list should be NERDs.
Print out a little sentence like this for each person:
Alvin is a DORK.
To create an String array you do the following:
<![CDATA[
String[] list = new String[]{ "one", "two", "three" };
]]>