Casting entire array of objects to string

问题

I have an array of type object which are strings. I would like to convert them to strings. What would be the quickest way of doing so?

Eg.: I have this object[] and want to convert it so it is this string[].

UPDATE: I think the problem is that some of the objects on the object[] are actually other objects like integers. I would need to convert them to strings first. Please include that into your solution. Thanks.

回答1:

Probably not the most efficient way to do it...it has the benefit of working when the objects aren't necessarily strings.

string[] output = (from o in objectArray
                   select o.ToString()).ToArray()

回答2:

object[] data = new object[] { "hello", "world", "!" };

string[] stringData = data.Cast<string>().ToArray();

If your object array contains mixed elements you can use the ConvertAll method of Array:

object[] data = new object[] { "hello", 1, 2, "world", "!" };

string[] stringData = Array.ConvertAll<object, string>(data, o => o.ToString());

回答3:

string[] output = Array.ConvertAll(objects, item => item.ToString());

回答4:

string[] myStringArray = myObjectArray.Cast<string>().ToArray();

or if you are using var keyword:

var myStringArray = myObjectArray.Cast<string>();

Using Cast will not throw an exception if any of your strings are null.

回答5:

 object[] objects;
 ..
 string[] result = Array.ConvertAll(objects, 
        new Converter<object, string>(Obj2string));
 public static string Obj2string(object obj)
 {
    return obj.ToString();
 }

回答6:

string[] str = new string[myObjects.Length];
for (int i = 0; i < myObjects.Length; ++i)
    str[i] = myObjects[i].ToString();

OR:

List<string> lst = new List<string>();
foreach (object o in myObjects)
    list.Add(o.ToString());
return list.ToArray();

回答7:

object[] data = new object[] { "hello", "world", 1, 2 };

string[] strings = data.Select(o => o == null ? null : o.ToString()).ToArray();

Crazy question update there...

回答8:

Since all objects are already strings the hard cast work. A safer way might be using the following:

  private static void Conversions()
  {
     var strings = Convert(new object[] {"a", "b"});
     var strings2 = Convert(new object[] {});
  }

  private static string[] Convert(IEnumerable<object> objects)
  {
     return objects as string[] ?? new string[] {};
  }

This implementation returns always a string array, potentially empty. Client side code can be implemented based on that assumption and you avoid having to check the return value for null.

回答9:

You can't use Enumerable.Cast if some of the object in the array are integers, it'll throw InvalidCastException when you do this:

var list = new object[] { "1", 1 };

list.Cast<string>();

Instead, try cristobalito's answer, or the lambda syntax equivalent:

list.Select(o => o.ToString()).ToArray();

来源：https://stackoverflow.com/questions/3394703/casting-entire-array-of-objects-to-string

标签

string

.net-3.5

object

casting