Common Objective-C NSString and nsstring Methods

Common Objective-C NSString and nsstring Methods

Tip: the previous ones are more common.

1. Create a string

Instance method:

-(Instancetype) initWithFormat :( NSString *) format

Format to generate a String object

This method is commonly used and has powerful functions. Usage: [[NSString alloc] initWithFormat: @ "I am student at % @ of Technology", @ "GuangDong University"];

-(Instancetype) initWithString :( NSString *) aString

Generates a String object based on the given string.

-(Instancetype) initwithuf8string :( const char *) bytes

UTF-8 encoding format C string to generate a String object

-(Instancetype) initWithCharacters :( const unichar *) characters

Length :( NSUInteger) length

Generates a String object based on the given C string (unencoded) and string length.

 

Class method:

+ (Instancetype) stringWithFormat :( NSString *) format ,...

Format and generate a string

+ (Instancetype) stringWithString :( NSString *) aString

+ (Instancetype) stringWithCharacters :( const unichar *) chars

Length :( NSUInteger) length

+ (Instancetype) stringWithCString :( const char *) cString

Encoding :( NSStringEncoding) enc

+ (Instancetype) stringwithuf8string :( const char *) bytes

 

 

2. Common attributes

@ Property (readonly) NSUInteger length

Returns the string length.

 

@ Property (readonly, copy) NSString * uppercaseString;

Converts lowercase letters in a string to uppercase letters.

@ Property (readonly, copy) NSString * lowercaseString;

Converts uppercase letters in a string to lowercase letters.

@ Property (readonly, copy) NSString * capitalizedString;

Converts the first letter of a word in a string to a uppercase letter, and the rest to lowercase letters.

 

@ Property (readonly) double doubleValue

@ Property (readonly) float floatValue

@ Property (readonly) int intValue

@ Property (readonly) NSInteger integerValue

@ Property (readonly) long longLongValue

@ Property (readonly) BOOL boolValue

Obtain the basic data type of the string.

Call method: str. uppercaseString; str. lowercaseString; str. capitalizedString (Instance name. attribute name)

 

 

3. Common Methods:

-(NSString *) stringByAppendingFormat :( NSString *) format ,...

Add a formatted string after the string

-(NSString *) substringFromIndex :( NSUInteger)AnIndex

Substring truncation (starting from anIndex position character (inclusive) to string end)

-(NSString *) substringToIndex :( NSUInteger)AnIndex

Substring truncation (truncates a string of anIndex characters from 0)

-(BOOL) containsString :( NSString *)Str

Judge whether the string contains the str string

-(BOOL) hasPrefix :( NSString *)AString

Whether the string contains the aString prefix

-(BOOL) hasSuffix :( NSString *)AString

Whether the string contains the aString suffix

-(BOOL) isw.tostring :( NSString *)AString

Judge whether the string and aString are equal

-(Nsange) rangeOfString :( NSString *)AString

Search for the range of the aString in the string that calls the method (start position and length)

-(NSString *) stringByReplacingOccurrencesOfString :( NSString *)TargetWithString :( NSString *)Replacement

Replacement string with the substring target in the string

-(NSString *) stringByReplacingCharactersInRange :( nsange)Range

WithString :( NSString *)Replacement

Replace the string in the range specified by range in the string with the replacement string.

-(NSComparisonResult) compare :( NSString *)AString

Compare string and astring

-(NSString *) stringByAppendingString :( NSString *) aString

Add a string aString after the string

-(NSString *) substringWithRange :( nsange)ARange

Substring truncation (the range is determined by the location and length in aRange)

Use NSMakeRange (NSUInteger loc, NSUInteger len) to obtain

-(Unichar) characterAtIndex :( NSUInteger) index

Obtains the character at the index position of the string (starting from 0 ).

-(Void) getCharacters :( unichar *) buffer

Store string content characters in the cache buffer

-(Void) getCharacters :( unichar *) buffer

Range :( nsange) aRange

Store the characters in the range specified by range to the buffer.

 

 

Note:

NSMutableString (variable string)

Variable classes must be initialized before definition.

-(Void) appendFormat :( NSString *)Format,...

Append the formatted string after the string

-(Void) appendString :( NSString *)AString

Add a string aString after the string

-(Void) deleteCharactersInRange :( nsange)ARange

Deletes a string in the range specified by aRange.

-(Void) insertString :( NSString *)AString

AtIndex :( NSUInteger)AnIndex

Insert the string aString at the anIndex position

-(Void) replaceCharactersInRange :( nsange)ARange

WithString :( NSString *) AString

Replace the string in the range specified by aRange with aString.

-(Void) setString :( NSString *)AString

Set the string to the specified string aString