Comparable Interface in Salesforce

In order to sort the wrapper class records,we need to implement comparable interface.
Example:
Apex Class:
global class EmployeeSalary {    
    public List<Employee> employeeList {get;set;}  

    public EmployeeSalary() {
        EmployeeList = new List<Employee>();
        Employee emp1= new Employee ('Mahesh', 120000);
        EmployeeList.add(emp1);
       
        Employee emp2 = new Employee ('Arun', 30000);
        EmployeeList.add(emp2);
       
        Employee emp3 = new Employee ('Suresh', 32000);
        EmployeeList.add(emp3);
       
        Employee emp4 = new Employee ('Kailash', 32000);
        EmployeeList.add(emp4);
        EmployeeList.sort();
    }
   
    //wrapper class for Comparable Interface
    global class Employee implements Comparable {
        global String employeName{get;set;}  
        global Integer salary {get; set;}
       
        global Employee (String Name, Integer salary) {
            employeName = Name;
            this.salary = salary;
        }
       
        global Integer compareTo(Object ObjToCompare) {
            return employeName.CompareTo(((Employee)ObjToCompare).employeName);
        }
    }
}
Visualforce Page :
<apex:page showHeader="false" controller="EmployeeSalary" >
<apex:form >
    <apex:pageBlock >
        <apex:pageblockTable value="{!employeeList}" var="e">
            <apex:column value="{!e.employeName}"/>
            <apex:column value="{!e.salary}"/>
        </apex:pageblockTable>
    </apex:pageBlock>
</apex:form>    
</apex:page>
Output :

How to delete an apex class or trigger from production org in salesforce

Steps :
Step 1:Open the sandbox org in force.com IDE(Eclipse).
Step 2:Open the matching .xml file of the class/trigger which we need to delete and change the status XML tag from "Active" to "Deleted".
Step 3:Save the file and then deploy the main class as well as associated .xml file to production.

How to change tab name( browser tab name) of Visualforce Page

Solution: Use document.title to give title.
Visualforce Page :
<apex:page>
<script type="text/javascript">
document.title = 'See Tab Name';
</script>

</apex:page>
Output :

Line Chart in Visualforce Page

Apex Class: 
public class LineChartController {
    // Return a list of data points for a chart
    public List<DataWrapper> getData() {
        return LineChartController.getChartData();
    }
    public static List<DataWrapper> getChartData() {
        List<DataWrapper> dataWrap= new List<DataWrapper>();
        dataWrap.add(new DataWrapper('JAN', 30));
        dataWrap.add(new DataWrapper('FEB', 44));
        dataWrap.add(new DataWrapper('MAR', 25));
        return dataWrap;
    }
   
    // Wrapper class
    public class DataWrapper {
        public String name { get; set; }
        public decimal data { get; set; }
        public dataWrapper(String name, integer value) {
            this.name = name;
            this.data = value;
        }
    }

}

Visualforce Page :

<apex:page controller="LineChartController">

    <apex:chart height="400" width="700" data="{!data}">

          <apex:axis type="Numeric" position="left" fields="data" 

            title="Opportunities Closed" grid="true"/>

          <apex:axis type="Category" position="bottom" fields="name" 

            title="Month of the Year">

        </apex:axis>

        <apex:lineSeries axis="left" fill="true" xField="name" yField="data"

          markerType="cross" markerSize="4" markerFill="#FF0000"/>

   </apex:chart>

</apex:page>

Output :