Methods of Objective-c NSString

Today the main practice nsstring nsmutablestring Nsarray Nsmutablearray

NSString ( string)

Method 1: [[NSString alloc] initwithformat:@ ""] creates a string object, formats it, and assigns a value to the string object

method 2:stringwithformat:@ "" structure equals [[NSString alloc]initwithformat:@ "]; convenience Builder to create a string

The 3:stringwithutf8string method converts a C string to an OC string object, which is important Note: I am a C -language string, so I do not add @ symbols

the above method is to understand NSString below we introduce the NSString of the three methods

creates a string object and assigns a value to the string object a Web site

NSString *str = [[NSString alloc] initwithformat:@ "http://item.taobao.com/item.htm?spm=a230r.1.14.83.wdbg0h &id=44327943363&ns=1&abbucket=2#detail"];

1. gets the length of the string keyword

Nsinteger length = [str length];

2. converts a string object to an uppercase keyword uppercasestring

NSString *upperstr = [str uppercasestring];

3. turns a string object into a lowercase keyword lowercasestring

NSString *lowerstr = [str lowercasestring];

4. decision string Start keyword: hasprefix

BOOL isbegin = [str hasprefix:@ "http:"];

1 means yes or TRUE

5. determine the end of string keyword Hassuffix

BOOL isend = [str hassuffix:@ "http:"];

6. stitching A string keyword: stringbyappendingstring Note: will be used frequently

NSString *appendstr = [str stringbyappendingstring:@ "/pinjie"];

7. to replace a string with a keyword: stringbyreplacingoccurrencesoffstring

Note : The replacement is a string , not a character

NSString *replacestr = [str stringbyreplacingoccurrencesofstring:@ "http" withstring:@ "MMMM"];

8. to compare keywords to a string : Compare Note: It is often used

Note : If the print result is 1, the front small if 0 means two equals if 1 indicates the front of the large

Nsinteger result = [@ "cc" compare:@ "BB"];

9. determine if a string is equal keywords: isequaltosting

BOOL isequal = [@ "AB" isequaltostring:@ "AC"];

10.1 intercept string keyword: substringfromindex

NSString *substr1 = [str substringfromindex:10];

Substringfromindex: indicates that the end of the string is truncated from the given subscript ( including the current subscript);

10.2 intercept string keyword: substringtoindex

NSString *SUBSTR2 = [str substringtoindex:25];

intercepts the first character to the 25th one

10.3 intercept string keyword: substringwithrange

There are many ways to quickly create structures in OC, starting with Nsmake + corresponding struct names, for example: (Nsmakerange ( position) ( length))

NSString *rangestr = [Str substringwithrange:nsmakerange (7, 25)];

11. gets the range of the string rangeofstring

Nsrange range = [str rangeofstring:@ "Taobao"];

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

12. Convert base type to string keyword: initwithformat

NSString *intstr = [[NSString alloc] initwithformat:@ "%d", 10];

NSString *intstr = @ "ten";// Laughter grammar

for the NSString object, It is not possible to change, no matter what the above method does to NSString , does not have the table NSString itself, Instead, it changed the copy of the nsstring.

if you want to change the nsstring itself, then you need to use its subclasses nsmutablestring on the basis of the above methods, more and more deleted

nsmutablestring *strmut = [[Nsmutablestring alloc] initwithformat:@ " I am a mutable string"];

Insert Method keywords: insert

[Strmut insertstring:@ " haha" atindex:8];

NSLog (@ "%@", Strmut);

The result is : I am a mutable string haha

Stitching Method Key words: Append

[Strmut appendstring:@ "/What Are you Laughing"];

The result is : I am a mutable string haha /What are you laughing at?

Delete method keyword: delete

[Strmut Deletecharactersinrange:nsmakerange (6,7)];

Reset Method keyword: set

[Strmut setstring:@ " I have been changing"];

Nsarray (Array)

Create three string objects

NSString *str1 = [NSString stringwithformat:@ "IPhone4"];

NSString *STR2 = [[NSString alloc] initwithformat:@ "IPhone5"];

NSString *STR3 = @ "IPhone6";

NSLog (@ "%@%@%@", STR1,STR2,STR3);

Nsarray

method 1:initwithobjects because it is an array, you need to pass in multiple objects, which are separated by "," and end with nil.

Create an Array object to receive the incoming objects .

Nsarray *arr1 = [[Nsarray alloc] initwithobjects:str1,str2,str3, nil];

NSLog (@ "%@", arr1);

Method 2:objectatindex: Finding an object by subscript will only find the first conforming object , even after the first object is not displayed , after the first one is found, it returns back .

NSString *str = [arr1 objectatindex:1];

NSLog (@ "%@", str);//nsstring type IPhone5

Nsinteger index = [arr1 INDEXOFOBJECT:STR2];

NSLog (@ "%ld", index),//arr1 subscript 1

Method 3: View the number of array elements

Nsinteger count = [arr1 count];

NSLog (@ "%ld", count);// Result: There are 3 elements in arr1

Method 4: Print out individual elements by facilitating

for (int i = 0; i < Arr1.count; i++) {

NSLog (@ "%@", [arr1 objectatindex:i]);

}

Method 5: sort sortedarrayusingselector: @selector (compare:) This method is provided by the system, the interior has been sorted, so know the method is good, There is no need for undue investigation.

Nsarray *sortarray = [arr1 sortedarrayusingselector: @selector (compare:)];

NSLog (@ "%@", Sortarray);

Nsmutablearray (variable group)

Nsmutablearray inheritance and Nsarray so Nsarray method Nsmutablearray can also be used

creating a mutable Array object

Nsmutablearray *mutarray = [[Nsmutablearray alloc] initwithobjects:str1,str3, nil];

Method 1: add addobject

[Mutarray ADDOBJECT:STR1];

[Mutarray ADDOBJECT:STR2];

[Mutarray ADDOBJECT:STR3];

NSLog (@ "%@%@%@", STR1,STR2,STR3);

Method 2: Delete the Removeobjectatindex

[Mutarray removeobjectatindex:1];

[Mutarray removeobjectatindex:0];

[Mutarray Removeobjectatindex:2];

NSLog (@ "%@", Mutarray);

Method 3: swap exchangeobjectatindex:

[Mutarray exchangeobjectatindex:1 withobjectatindex:0];

NSLog (@ "%@", Mutarray);

Method 4: sort sortusingselector: @selector (compare:)

nsstring *str1 = @ "Jack";

nsstring *str2 = @ "Henry";

nsstring *STR3 = @ "Elyse";

nsstring *STR4 = @ "John";

nsstring *STR5 = @ "Justin";

Nsmutablearray *mutablearray = [[nsmutablearray alloc] INITWITHOBJECTS:STR1,STR2,STR3,STR4,STR5, Nil];

[Mutablearray Sortusingselector:@selector (compare:)];

NSLog (@ "%@", Mutablearray);

Method 5: Get the first element of the array firstobject

[Mutablearray firstobject];

NSLog (@ "%@", Mutablearray. Firstobject);

Method 5: get the last element of the array

[Mutablearray lastobject];

NSLog (@ "%@", Mutablearray. Lastobject);

}

return 0;

Methods of Objective-c NSString