How to run Java programs using cmd
Prerequisites
JDKshould be installed.
To download and install JDK, follow the link below:
Executing a Java program
Step 1:
Before running any Java program, the first step is to check if the Java Development Kit (JDK) is available on our Systems.
To check for the availability of Java, run the following command on any terminal:
java -version
Step 2:
In the next step, we will rite a Java program. Here, we will consider a simple “Hello World!” program, as shown below.
class test{public static void main( String args[] ){System.out.println( "Hello World!" );}}
Now, since Java is both a compiled as well as an interpreted language, we first need to compile our Java-Script. This then creates a Java Byte code that is independent of the platform upon which it has to run. Then, the
Java Byte codeis converted, line-by-line, to machine code by,i.e., the Java Interpreter. JVM Java Virtual Machine
Step 3:
To compile our Java program, we need to tell the Java compiler which program to compile. This can be done by:
javac test.java
If no errors exist, then the program will be successfully compiled and the terminal will take you to the next line. If an error exists, we are bound to get some error messages.
Step 4:
Now, after a successful compilation, we need to execute the byte code to get our output from the program. This is done as follows:
java test
Note: While executing the Java program, we should be on the same directory where the file is present.
Assumption: Path Variable is set.
