Import statement usage in Java

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Introduction

Import statements let you use code from other places easily. They save time and keep your code clean.

When you want to use a class from another package without writing its full name every time.

When you want to organize your code by using libraries or built-in Java classes.

When you want to avoid repeating long package names in your code.

When you want to use multiple classes from the same package.

When you want to make your code easier to read and maintain.

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Syntax

Java

import packageName.ClassName;

// or to import all classes in a package
import packageName.*;

The import statement must be placed at the top of your Java file, before any class definitions.

Using * imports all classes in a package but does not import sub-packages.

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Examples

line_end_arrow_notchThis imports only the Scanner class from the java.util package.

Java

import java.util.Scanner;

line_end_arrow_notchThis imports all classes from the java.util package, like Scanner, ArrayList, etc.

Java

import java.util.*;

line_end_arrow_notchThis imports the static constant PI from the Math class, so you can use PI directly.

Java

import static java.lang.Math.PI;

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Sample Program

This program uses the Scanner class to read user input. The import statement lets us use Scanner without writing java.util.Scanner every time.

Java

import java.util.Scanner;

public class ImportExample {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter your name: ");
        String name = scanner.nextLine();
        System.out.println("Hello, " + name + "!");
        scanner.close();
    }
}

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Important Notes

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Import statements do not import code automatically; they just let you use names without full paths.

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If you forget to import a class, Java will show an error saying it cannot find the symbol.

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You can also use fully qualified names without import, but it makes code longer and harder to read.

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Summary

Import statements help you use classes from other packages easily.

Place import statements at the top of your Java file.

You can import single classes or all classes from a package using *.