Static Import and access modifiers
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This document discusses static import and access control in Java. It explains that static import allows importing static members without specifying the class name. This improves readability. Access specifiers like private, default, protected, and public define the scope and visibility of class members. Private members can only be accessed within the class, while public members can be accessed anywhere. The document provides examples to illustrate static import and how access specifiers work.
![Static Import
For Example:
class A
{
Public static void main(String a[])
{
Int a=36;
Int val=Math.sqrt(a);
4](https://image.slidesharecdn.com/javaala1-170828133023/85/Static-Import-and-access-modifiers-4-320.jpg)
![Static Import
Import static java.lang.System.out;
Import static java.lang.Math.sqrt;
class A
{
Public static void main(String a[])
{
6](https://image.slidesharecdn.com/javaala1-170828133023/85/Static-Import-and-access-modifiers-6-320.jpg)
![Access control
C=a*b;
System.out.println(“mul is”+c);}}
class xyz
{
Public static void main(String a[])
{
13](https://image.slidesharecdn.com/javaala1-170828133023/85/Static-Import-and-access-modifiers-13-320.jpg)
Static Import and access modifiers
- 1. Object Oriented Programming Language Vadodara Institute of Engineering Active Learning Assignment Topic: Static Import and Access Control Computer Engineering Presented By: Kashyap Patel 150800107046 Krishna Patel 150800107047 Maitree Patel 150800107048 1
- 2. Contents Static Import Access control 2
- 3. Static Import • Static Import is a new feature added in java. • In order to access static members, it is necessary to qualify references with the class they came from. • That means in order to access the static members of a class, it is a must to write the member along with its belonging class name. 3
- 4. Static Import For Example: class A { Public static void main(String a[]) { Int a=36; Int val=Math.sqrt(a); 4
- 5. Static Import System.out.println(“The square root of”+a”is”+val); } } o/p : The square root of 36 is 6 In order to avoid unnecessary use of static class members like Math and System, we should Static import. 5
- 6. Static Import Import static java.lang.System.out; Import static java.lang.Math.sqrt; class A { Public static void main(String a[]) { 6
- 7. Static Import Int a=36; Int val=sqrt(a); System.out.println(“the square root of”+a”is”+val); } } • O/p : the square root of 36 is 6 7
- 8. Static Import • Note that ambiguous static import is not allowed. • That means two different classes referencing the same functionality is not allowed. Advantage: • The advantage of using static import is that readability of the code increases as it avoids writing of belonging class name each time. 8
- 9. Access control • Access specifiers: visibility modifiers. – Private – default – protected – public • these specifiers specify the scope . 9
- 10. Access control • Private members can be accessed within the class where they are declared. They are not allowed outside the class. • Top level classes can be default and public but not private • we can use these 4 specifies for all the members of the class • these specifiers are not allowed for local variables 10
- 11. Access control Class A { private int a; Void set_a(int i) { A=I; }} Declared private 11
- 12. Access control class B extends A { int b; Void set_b(int i) { B=i; } Void mul() { Int c; 12
- 13. Access control C=a*b; System.out.println(“mul is”+c);}} class xyz { Public static void main(String a[]) { 13
- 14. Access control A a=new A; B b=new B; b.set_a(10); b.set_b(4); b.mul(); } } 14
- 16. Thank You 16