[Solved] assign value to a field in a list using linq

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public class Worker 
{
    public string Name {get;set;}
    public string CompanyId {get;set;}
    public string CompanyName {get;set;}
}

public class Company
{
 public string Name {get;set;}
 public string Id {get;set;}
}


   var companyList = new List<Company>
    {
        new Company{Id = "1", Name = "Company 1"},
        new Company{Id = "2", Name = "Company 2"},
        new Company{Id = "3", Name = "Company 3"}
    };

    var workerList = new List<Worker>
    {
        new Worker{ Name = "Worker 1", CompanyId = "2" },
        new Worker{ Name = "Worker 2", CompanyId = "1" },
        new Worker{ Name = "Worker 3", CompanyId = "2" },
        new Worker{ Name = "Worker 4", CompanyId = "3" },
        new Worker{ Name = "Worker 5", CompanyId = "1" }
    };

workerList.ForEach(w => {
            w.CompanyName = companyList.FirstOrDefault(c=>c.Id == w.CompanyId)?.Name;
        });


foreach(var w in workerList)
{
    Console.WriteLine(w.Name+"-"+w.CompanyName);
    // ==> output will be
    //Worker 1-Company 2
    //Worker 2-Company 1
    //Worker 3-Company 2
    //Worker 4-Company 3
    //Worker 5-Company 1
}

Or if the idea is to understand Join in Linq, then 

var workers =   (from worker in workerList
                join company in companyList
                on worker.CompanyId equals company.Id
                select new Worker 
                 {
                    Name = worker.Name,
                    CompanyId = worker.CompanyId,
                    CompanyName = company.Name
                 }).ToList();

solved assign value to a field in a list using linq