Curriculum
Throw vs Throws in Java are important exception handling concepts used to create, declare, and manage exceptions in Java applications. These keywords help developers build secure, reliable, and maintainable software systems.
In this Core Java course in Jaipur, students will learn throw keyword in Java, throws keyword in Java, difference between throw and throws, custom exception handling, checked exceptions, and practical examples used in software development.
throw and throws are widely used in:
Understanding throw vs throws in Java helps students manage exceptions professionally in real-world software development.
The:
throwkeyword is used to:
Developers use throw when:
throw new ExceptionType("message");class ThrowExample {
public static void main(String[] args) {
int age = 15;
if(age < 18) {
throw new ArithmeticException("Not Eligible for Voting");
}
System.out.println("Eligible");
}
}Exception in thread "main" java.lang.ArithmeticException: Not Eligible for VotingHere:
throwmanually generates:
ArithmeticExceptionwhen condition becomes true.
throw keyword helps developers:
The:
throwskeyword is used to:
that may occur in method.
It informs:
about possible exceptions.
returnType methodName() throws ExceptionType {
}import java.io.IOException;
class ThrowsExample {
void checkFile() throws IOException {
throw new IOException("File Error");
}
public static void main(String[] args) {
ThrowsExample obj = new ThrowsExample();
try {
obj.checkFile();
} catch(IOException e) {
System.out.println(e);
}
}
}java.io.IOException: File ErrorHere:
throws IOExceptiondeclares possible exception.
The exception is handled using:
try-catchblock.
| throw | throws |
|---|---|
| Used to create exception | Used to declare exception |
| Used inside method | Used in method signature |
| Throws single exception | Can declare multiple exceptions |
| Followed by object | Followed by class names |
import java.io.IOException;
class Demo {
void checkNumber(int number) throws IOException {
if(number < 0) {
throw new IOException("Negative Number");
}
System.out.println(number);
}
public static void main(String[] args) {
Demo d1 = new Demo();
try {
d1.checkNumber(-5);
} catch(IOException e) {
System.out.println(e);
}
}
}java.io.IOException: Negative NumberCompiler checks checked exceptions during compilation.
Example:
These often require:
throwskeyword.
Unchecked exceptions occur during runtime.
Example:
These usually do not require:
throwsJava allows declaring multiple exceptions.
void process() throws IOException, SQLException {
}Developers can provide custom exception messages.
throw new ArithmeticException("Invalid Age");Exceptions move from:
until handled.
class Propagation {
void method1() {
int result = 10 / 0;
}
void method2() {
method1();
}
public static void main(String[] args) {
Propagation p1 = new Propagation();
try {
p1.method2();
} catch(Exception e) {
System.out.println("Exception Handled");
}
}
}Exception HandledHandling:
Handling:
Handling:
Handling:
These keywords provide:
Incorrect:
throws new Exception();Methods using:
throwsoften require handling.
Choosing incorrect exception reduces code quality.
Understanding throw and throws helps students:
In this lesson, students learned:
These concepts are essential for Java programming, backend development, and enterprise software systems.
throw keyword is used to explicitly generate exceptions.
throws keyword declares exceptions that may occur in method.
throw creates exception, while throws declares exception.
Yes, Java allows multiple exceptions with throws keyword.
throw helps developers generate custom exceptions and validate application logic.
They are used in banking systems, APIs, file handling systems, and enterprise software.