[Solved]-Match List<string> to List<object> using LINQ?-LINQ,C#

ok if you want to avoid forloop and do it with linq is still possible

here is what i gott

var lista = new list<string>();
    lista.add("test");
    lista.add("123");
    lista.add("5.7");

   var listb = new list<type>();
    listb.add(typeof(string));
    listb.add(typeof(int));
    listb.add(typeof(float));
   var index =-1;

try{
var newlist = lista.select((x, i)=>  convert.changetype(x, listb[(index = i)])).tolist();

}catch(exception e){

 throw  new exception("failed to cast value "+lista[index]+" to "+listb[index]);

}

you could zip the lists together, then use the convert.changetype method

returns an object of a specified type whose value is equivalent to a specified object.

it will throw an exception of the following types

• invalidcastexception this conversion is not supported. -or- value is null and conversiontype is a value type. -or- value does not implement the iconvertible interface.

• formatexception value is not in a format recognized by conversiontype.

• overflowexception value represents a number that is out of the range of conversiontype.

• argumentnullexception conversiontype is null.

example

var lista = new list<string> { "test", "123", "5.7" };
var listb = new list<type> { typeof(string), typeof(int), typeof(int) };
    
var combined = lista.zip(listb, (s, type) => (value :s, type:type));

foreach (var item in combined)
{
   try
   {
      convert.changetype(item.value, item.type);
   }
   catch (exception ex)
   {
      throw new invalidoperationexception($"failed to cast value {item.value} to {item.type}",ex);
   }
}

full demo here

_{side note: technically speaking this is not casting per se, it's changing/converting the type}

you could do the following with zip.

var result = lista.zip(listb,(value,type)=> 
                        { 
                           try{return convert.changetype(value,(type)type);} 
                           catch{throw new exception($"cannot cast between value {value} to type {type}");}
                        });

by having the conversion within the zip, would ensure you wouldn't have to convert the whole list if there is an exception earlier in the list.