C# 0 The Complete Reference

PART II

C h a p t e r   2 2 :  

S t r i n g s   a n d   F o r m a t t i n g    

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To search for the first occurrence of a character or substring, use the 

IndexOf( )

 method. 

Here are two of its forms:

public int IndexOf(char 

ch

)

public int IndexOf(String 

str

)

The first form returns the index of the first occurrence of the character 

ch

 within the invoking 

string. The second form returns the first occurrence of the string 

str.

 Both return –1 if the 

item is not found.

To search for the last occurrence of a character or substring, use the 

LastIndexOf( )

method. Here are two of its forms:

public int LastIndexOf(char 

ch

)

public int LastIndexOf(string 

str

)

The first form returns the index of the last occurrence of the character 

ch

 within the invoking 

string. The second form returns the index of the last occurrence of the string 

str.

 Both return 

–1 if the item is not found.

String

 offers two interesting supplemental search methods: