IPhone objective-C string nsstring usage

During the development process, we will encounter a lot of string operations. It is a common data type, and the usage of it is summarized below:

// 1. Create a constant string.

Nsstring * astring = @ "This Is
String! ";

// 2. Create an empty string and assign a value.

Nsstring * astring = [nsstring alloc]
Init];

Astring = @ "this is a string! ";

Nslog (@ "astring: % @", astring );

[Astring release];

// 3. In the preceding method, the speed is improved by using the initwithstring method.

Nsstring * astring = [nsstring alloc]
Initwithstring: @ "this is a string! "];

Nslog (@ "astring: % @", astring );

[Astring release];

// 4. Use Standard C to create a string: initwithcstring Method

Char * cstring = "This Is
String! ";

Nsstring * astring = [nsstring alloc]
Initwithcstring: cstring];

Nslog (@ "astring: % @", astring );

[Astring release];

// 5. Create a formatted string: A placeholder (consisting of one % and one character)

Int I = 1;

Int J = 2;

Nsstring * astring = [nsstring alloc]
Initwithstring: [nsstring stringwithformat: @ "% d. This is % I
String! ", I, j];

Nslog (@ "astring: % @", astring );

[Astring release];

// 6. Create a temporary string

Nsstring * astring;

Astring = [nsstring stringwithcstring: "This
Is a temporary string "];

Nslog (@ "astring: % @", astring );

Nsstring * Path = @ "astring. Text ";

Nsstring * astring = [nsstring alloc]
Initwithcontentsoffile: path];

Nslog (@ "astring: % @", astring );

[Astring release];

Nsstring * astring = [nsstring alloc]
Initwithstring: @ "this is a string! "];

Nslog (@ "astring: % @", astring );

Nsstring * Path =
@ "Astring. Text ";

[Astring writetofile: path atomically:
Yes];

[Astring
Release];

// Compare the strcmp function with C

Char string1 [] = "string! ";

Char string2 [] = "string! ";

If (strcmp (string1, string2) =
0)

{

Nslog (@ "1 ");

}

// Isequaltostring Method

Nsstring * astring01 = @ "This Is
String! ";

Nsstring * astring02 = @ "This Is
String! ";

Bool result = [astring01
Isequaltostring: astring02];

Nslog (@ "Result: % d", result );

// Compare method (three values returned by comparer)

Nsstring * astring01 = @ "This Is
String! ";

Nsstring * astring02 = @ "This Is
String! ";

Bool result = [astring01 compare: astring02]
= Nsorderedsame;

Nslog (@ "Result: % d", result );

// Determine whether the content of nsorderedsame is the same

Nsstring * astring01 = @ "This Is
String! ";

Nsstring * astring02 = @ "This Is
String! ";

Bool result = [astring01 compare: astring02]
= Nsorderedascending;

Nslog (@ "Result: % d", result );

// Nsorderedascending
Determine the size of the two object values (in alphabetical order, astring02 is true if it is greater than astring01)

Nsstring * astring01 = @ "This Is
String! ";

Nsstring * astring02 = @ "This Is
String! ";

Bool result = [astring01 compare: astring02]
= Nsordereddescending;

Nslog (@ "Result: % d", result );

// Nsordereddescending
Determine the size of the two object values (in alphabetical order, astring02 is true if it is smaller than astring01)

// Do not consider comparing strings with uppercase and lowercase letters 1

Nsstring * astring01 = @ "This Is
String! ";

Nsstring * astring02 = @ "This Is
String! ";

Bool result = [astring01
Caseinsensitivecompare: astring02] =
Nsorderedsame;

Nslog (@ "Result: % d", result );

// Nsordereddescending determines the size of the two object values (in alphabetical order, astring02 is smaller than astring01
True)

 

// How to judge whether the string is null

Nsstring * urlstring = [urlinput stringvalue];

If
(! Urlstring ){





Nslog (
@ "No input ."
);






}
Else
{



If
([Urlstring length] =
0
){





Nslog (
@ "No input ."
);





}
Else
{





}






}


}