get the build index of a scene by name unity code example

Example 1: how to get scene index unity

SceneManager.GetActiveScene().buildIndex;

Example 2: unity get scene name by index

private static string NameFromIndex(int BuildIndex)
 {
     string path = SceneUtility.GetScenePathByBuildIndex(BuildIndex);
     int slash = path.LastIndexOf('/');
     string name = path.Substring(slash + 1);
     int dot = name.LastIndexOf('.');
     return name.Substring(0, dot);
 }