How to implement JSON in Apex Salesforce

Apex Class : Write the following code in apex class:

public with sharing class JSONClass {
    
    /**
     * Webkul Software.
     *
     * @category  Webkul
     * @author    Webkul
     * @copyright Copyright (c) 2010-2016 Webkul Software Private Limited (https://webkul.com)
     * @license   https://store.webkul.com/license.html
     **/
    
    public list<Account> acc { get{
    	//Fetch the Account List
    	acc = [Select Id,Name,AccountNumber,AccountSource from Account where name != null limit 50000];
    	
    	if(acc==null){
    		acc = new list<Account>();    		
    	}
    	return acc;
    } set;}   
     
    public string jsonSerial {get{
		//JSON Class method    
   		if(acc==null){
    		jsonSerial = '';    		
    	}else{
    		jsonSerial = JSON.serialize(acc);
    	}
    	return jsonSerial; 	
    
    } set; }

     public string jsonGen { get{
         //JSON Generator Class method 
         JSONGenerator gen = JSON.createGenerator(false);//true gives output in pretty print
        
        if(acc==null){
            return '';          
        }else{
            
            gen.writeStartArray();
            
            for(Account a: acc){
                
                gen.writeStartObject();
                    
                    gen.writeStringField('Name', a.name);
                    gen.writeStringField('Id', a.Id);
                    if(a.AccountNumber==null)
                        gen.writeStringField('Account Number', '');
                    else{
                        gen.writeStringField('Account Number',a.AccountNumber); 
                    }

                    gen.writeEndObject();
                
            }
            
        gen.writeEndArray();
        return gen.getAsString();
          
        }
                
    } set; } 
    
}

Visualforce Page : Write the following code in Visualforce Page:

<apex:page controller="JSONClass">
    
    <!-- 
    /**
     * Webkul Software.
     *
     * @category  Webkul
     * @author    Webkul
     * @copyright Copyright (c) 2010-2016 Webkul Software Private Limited (https://webkul.com)
     * @license   https://store.webkul.com/license.html
     */
     -->

    <apex:form>
        
        <strong>Output through the list in data table</strong>:<br/><br/>   
        
        <apex:dataTable value = "{!acc}" var = "key">
            
            <apex:column>
                <apex:facet name = "header">Account Name</apex:facet>
                {!key.Name}
            </apex:column>
            
            <apex:column>
                <apex:facet name = "header">Account Number</apex:facet>
                {!key.AccountNumber}
            </apex:column>

        </apex:dataTable>
        
        <br/><br/>
        
        <strong>Output Via JSON serialize method</strong> :<br/><br/> {!jsonSerial}
        
        <br/><br/>
        
        <strong>Output Via JSON Generator method</strong> :<br/><br/> {!jsonGen}
        
    </apex:form>
    
</apex:page>

That’s all for how to implement JSON in Apex , still have any issue feel free to add a ticket and let us know your views to make the code better https://webkul.uvdesk.com/en/customer/create-ticket/