Java vs. Ruby Programming Language Comparison

Java and Ruby are two popular programming languages that represent two very different approaches to structure and syntax. Java has a more formal, strict syntax. Ruby syntax is more forgiving and provides many shortcuts and abbreviations. Java is compiled and Ruby is interpreted.

The table below shows a sampling of Java and Ruby programming language elements that highlight these differences.

JavaRuby
Block {
   . . .
}
def/class/do/if...
   . . .
end
Class
Definition
public class Hello {
   . . .
}
class Hello
   . . .
end
Class
Constructor
public Hello(Strng msg) {
    defaultMsg=msg;
}
def initialize(msg)
   . . .
end
Class
Instantiation
Hello mHello=new Hello();
mHello=Hello.new("Hello Ruby")
Class
Variable
static String myVariable; @@myVariable
Comment // Comment text. # Comment text.
Constant final static MY_CONSTANT; MY_CONSTANT
Conditional if (a>b) {
   . . .
}  else {
   . . .
}
if a>b
   . . .
else
   . . .
end
Exception
Handling
try { . . . }
catch { . . . }
raise . . .
 
Global
Variable
public class MyGlobals {
   public static String mG1
}
$mG1
 
 
Importing import java.sql.*; require 'extensions'
Inheritance extends MyClass < MyClass
Instance
Variable
// Declared outside methods
String mVariable;
@mVariable
 
Iteration for (i=0; i<5; i++) {
    . . .
}

for (myElement : myCollection){
    . . .
}
5.times do | i |
   . . .
end
Local
Variable
String myVariable; my_variable
Method
Definition
public void myIdea(String param) {
   . . .
}
def myIdea(param="Starter")
   . . .
end
Method
Use
myIdea(mParameter) myIdea m_parameter
Namespace
Reference
packageName;
: :
Null Value null
nill
Statement
Separator
;
new line
Variable String mString="Hello Java";
mString="Hello Ruby"