C# 0 The Complete Reference

IndexOfAny( )

 and 

LastIndexOfAny( )

. These search for the first or last character that matches any of a set of 

characters. Here are their simplest forms:

public int IndexOfAny(char[ ] 

a

)

public int LastIndexOfAny(char[ ] 

a

)

IndexOfAny( )

 returns the index of the first occurrence of any character in 

a

 that is found 

within the invoking string. 

LastIndexOfAny( )

 returns the index of the last occurrence of any 

character in 

a

 that is found within the invoking string. Both return –1 if no match is found.

When working with strings, it is often useful to know if a string begins with or ends 

with a given substring. To accomplish these tasks, use the 

StartsWith( )

 and 

EndsWith( )

methods. Here are their two simplest forms:

public bool StartsWith(string 

str

)

public bool EndsWith(string 

str

)