Bind checkbox value with controller boolean variable

Question

I have checkboxes on my vf page

<apex:inputCheckbox id="checkboxShowP" value="{!P}" onchange="show(this);"/>

In the controller class

public boolean P{get;set;}

I want to bind this checkbox value to a boolean variable. But when I display the P value of apex class it is showing up as null. Is it possible to bind variable values in this way?

Answer 1

Looks like you have not initialised the value for "P". Initialise the value in the constructor.

VF Page:

<apex:page controller="CheckboxController">
    <apex:form >
        <apex:inputCheckbox id="checkboxShowP" value="{!P}" onchange="show(this);"/>
    </apex:form>
</apex:page>

Apex Class:

public with sharing class CheckboxController {

    public Boolean P{ get; set; }

    public CheckboxController(){
        this.P = true;
    }
}

Do check the Apex and VF trailhead for an understanding of dynamic bindings.

Custom Controllers : https://developer.salesforce.com/docs/atlas.en-us.pages.meta/pages/pages_controller_custom.htm