.NET Framework 4.6 and 4.5
Searches for the specified object and returns the index of the first occurrence within the entire list.
public virtual int IndexOf(
- Type: System.Object
The Object to locate in the underlying list represented by the List property. The value can be null.
Type: System.Int32The zero-based index of the first occurrence of the value parameter; otherwise, -1 if value is not in the list.
Although the implementation is dependent on the underlying list's IndexOf method, typically the following characteristics apply:
The List is searched starting at the first element and ending at the last element.
The underlying method performs a linear search; therefore, the average execution time is proportional to the value of the Count property.
The underlying method determines equality by calling the Equals method.
Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0
.NET Framework Client Profile
Supported in: 4, 3.5 SP1