Basic OC string operations and basic oc operations

Basic OC string operations and basic oc operations

The variable string modification method has a return value (re-pointing to the new string address)

The variable string modification method does not return values (modifying the string itself)

/*

NSString immutable string

*/

// 1. Create a String object

// Use the initialization method to create an object

NSString * string1 = [[NSString alloc] initWithFormat: @ "hello, world"];

 

// Use the Class Method

NSString * string2 = [NSString stringWithFormat: @ "hello, world"];

 

// Use literal

NSString * string3 = @ "hello, kitty ";

 

 

// 2. Get the string length

NSLog (@ "string1length = % ld", string1.length );

NSLog (@ "string1length = % ld", [string1 length]);

 

 

// 3. Get the characters at the specified position

Unichar ch = [string2 characterAtIndex: 3];

NSLog (@ "ch = % c", ch );

 

 

// 4. Determine the prefix and suffix of a string

NSString * string4 = @ "www.oba .png ";

BOOL isHasSuffix = [string4 hasSuffix: @ ". png"];

BOOL isHasPrefix = [string4 hasPrefix: @ "www."];

NSLog (@ "isHasSuffix = % d, isHasPrefix = % d", isHasSuffix, isHasPrefix );

 

// 5. Search for the range of a string in another string

NSString * string5 = @ "surging clouds ";

NSString * string6 = @ "";

// A struct in the specified range contains two parts.

// Location indicates the start position and length indicates the length

Nsange range = [string5 rangeOfString: string6];

NSLog (@ "location = % ld, length = % ld", range. location, range. length );

 

 

// 6. String Truncation

NSString * string7 = @ "hello world kitty ";

 

// Truncate a string within a specified range

Nsange range1 = NSMakeRange (0, 5 );

NSString * subStr1 = [string7 substringWithRange: range1];

NSLog (@ "% @", subStr1 );

 

// Capture a certain length from the beginning

NSString * subStr2 = [string7 substringToIndex: 5];

NSLog (@ "% @", subStr2 );

 

// Extract from the specified position and backward, including the subscript position of the specified position

NSString * subStr3 = [string7 substringFromIndex: string7.length-5];

NSLog (@ "% @", subStr3 );

 

 

// 7. String concatenation

NSString * string8 = @ "nana ";

NSString * string9 = @ "liuaoran ";

NSString * love = [string8 stringByAppendingString: string9];

// NSString * love1 = [NSString stringWithFormat: @ "% @", string8, string9];

NSLog (@ "love = % @", love );

 

 

// 8. String replacement

NSString * string10 = @ "Li Yifeng ";

NSString * string11 = [string10 stringByReplacingOccurrencesOfString: string10 withString: @ "Zhao lived"];

NSLog (@ "% @", string11 );

 

 

// 9. String comparison

NSString * string12 = @ "wangcai ";

NSString * string13 = @ "xiaoqiang ";

NSInteger result = [string12 compare: string13];

NSLog (@ "% ld", result );

 

// Determine whether two strings are equal

BOOL isEqual = [string12 isw.tostring: string13];

NSLog (@ "% d", isEqual );

 

 

// 10. String and numeric type conversion

NSString * string14 = @" 123 ";

NSInteger value1 = [string14 integerValue];

NSLog (@ "% ld", value1 );

 

 

// 11. String case-insensitive Conversion

NSString * string15 = @ "da feng qi xi yun fei yang ";

NSString * string16 = @ "Da Feng Qi Xi Yun Fei Yang ";

 

// Uppercase letters

NSString * str1 = [string15 capitalizedString];

NSLog (@ "% @", str1 );

 

// All uppercase letters

NSString * str2 = [string15 uppercaseString];

NSLog (@ "% @", str2 );

 

// All lowercase letters

NSString * str3 = [string16 lowercaseString];

NSLog (@ "% @", str3 );

 

 

 

/**

* NSMutableString

*/

// 1. Create an object

// Initialization Method

NSMutableString * mStr1 = [[NSMutableString alloc] initWithFormat: @ "hello, world"];

 

// Class Method

NSMutableString * mStr2 = [NSMutableString stringWithFormat: @ "hello kitty"];

 

// You cannot create a string using a literal, because all strings created using a literal are immutable.

 

 

// 2. concatenate a string

NSMutableString * mStr3 = [NSMutableString stringWithFormat: @ "Wei Zhuang"];

[MStr3 appendString: @ ""];

NSLog (@ "% @", mStr3 );

 

// 3. Insert a string

[MStr2 insertString: @ "," atIndex: 5];

NSLog (@ "% @", mStr2 );

 

 

// 4. delete a string

[MStr1 deleteCharactersInRange: NSMakeRange (5, 1)];

NSLog (@ "% @", mStr1 );

 

 

// 5. String replacement

NSMutableString * mStr4 = [NSMutableString stringWithFormat: @ "Tian Ming and Shao Yu are good buddies"];

[MStr4 replaceCharactersInRange: NSMakeRange (3, 3) withString: @ "Er"];

NSLog (@ "% @", mStr4 );

 

 

// 6. Reset the string

[MStr4 setString: @ "starsoul"];

NSLog (@ "% @", mStr4 );