APEX Introduction

 APEX Introduction

It is Object oriented programming language that is used to provide custom code to create business logic and database operation.

APEX is also used to create salesforce triggers that will work automatically , before and after database operation(Insert, Update, Delete).

Apex provide SOQL and SOSL to manage database operation.

SOQL means salesforce Object Query Language and SOSL means salesforce  object search language,

APEX language syntax is similar to Java programming language, it will compile and execute code using Apex cloud compiler.

Salesforce provide developer option to create APEX class and execute option to execute APEX Code.

Syntax of Apex

public class Classname{

   public static retuntype Methodname() {

  }

  public retuntype Methodname() {

  }

}

Execute Apex code:-

Classname ref = new Classname();

ref.methodname();

Static method means it will store data under class memory that's why it would be call by Classname.

Instance Method means dynamic, it will store data under external memory space that's why first we create memory space using object after that we can call method.

to create dynamic memory space, we will create object.

Classname ref = new Classname();  // it is the syntax object.

ref means address of object, new means memory allocation and Classname() is the constructor that is used to create the memory space.

Now I am creating sample program to differentiate static and dynamic

public class Hello {

  public static void DisplayHello()

  {

      System.debug('hello world');

  }

  public void DisplayHello1()

  {

      System.debug('welcome in salesforce');

  }

}

Press Ctrl + e to open execute window and write followings code.

Hello.DisplayHello();

Hello obj = new Hello();

obj.DisplayHello1();

Now i am creating another program to perform addition and subtraction in APEX class, where addition method is static and subtraction method is dynamic.

Solution:-

public class Operation {

static integer a,b,c;

integer x,y,z;

public static void add()

{

    a=100;

    b=200;

    c=a+b;

    System.debug('result is '+c);

}

public void sub()

{

    x=100;

    y=200;

    z=x-y;

    System.debug('result is '+z);

}

}

Execute this program:-

Operation.add();

Operation obj = new Operation();

obj.sub();

Assignment:-

1)  Manage Employee Information with empid, empname, job, salary, joingdate, experience, dateofbirth with respective data type.

public class Employee {

private integer empid;

private string empname;

private string job;

private integer salary;

private double experience;

private date dob;

private date joiningdate;

public void Accept(integer empid,string empname,string job,integer salary,double experience,date dob,date joiningdate)

{

    this.empid=empid;

    this.empname=empname;

    this.job=job;

    this.salary=salary;

    this.experience=experience;

    this.dob=dob;

    this.joiningdate=joiningdate;

}

public void Display()

{

    System.debug('empid is '+empid + ' name is '+empname + ' job is '+job + 'salary is '+salary + 'experience is '+experience + ' dob is '+dob + ' Joining date is '+ joiningdate);

}

    

}

How to call it:-

Employee obj = new Employee();

obj.Accept(1001,'emp1','cleark',45000,2.5d,date.valueOf('1992-12-12'),date.valueOf('1992-12-12'));

obj.Display();

2)  Calculate Simple Interest using APEX Class

3)  WAP to swap two different numbers?

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