Let's continue to talk about the fraction class in objective-C separation interface and implementation file. If there is a way to set numerator with only one message
At the same time, you can set denominator. How nice is that! No problem. By listing each continuous method and connecting it with a colon, you can define an accept
Multiple ParametersOf
Method. Parameters connected by colons are part of the method name. For example, the method name addentrywithname: andemail indicates the method for receiving two parameters, which may be the name and email address. Method
Addentrywithname: andemail: andphone: a method that receives the following three parameters: a name, an email address, and a phone number.
At the same time, the numerator and denominator methods can be set to setnumerator: anddenominator: You can take the following form:
[Myfraction setnumerator: 1 anddenominator: 3];
This method is not bad. In fact, this is the preferred method for naming. However, you must specify a name that is easier to read for the method. For example, setto: over is a more general practice, which is more readable than the previous one.
[Myfraction setto: 1 over: 3];
Next, let's apply this new method to fraction. h:
01 # Import
<Foundation/Foundation. h>
02
03 // Define the fraction class
04
05 @ Interface Fraction: Nsobject
06 {
07 Int Numerator;
08 Int Denominator;
09 }
10
11 @ Property Int Numerator, Denominator;
12
13 -(Void) Print;
14 -(Void) Setto: (INT) N Over: (INT) D;
15 -(Double) Converttonum;
16
17 @ End
Then, add a new method definition in the implementation file:
01 # Import
"Fraction. H"
02
03 @ Implementation Fraction
04
05 @ Synthesize Numerator, Denominator;
06
07 -(Void) Print
08 {
09 Nslog (@ "% I/% I ", Numerator, Denominator );
10 }
11
12 -(Double) Converttonum
13 {
14 If (Denominator ! = 0)
15 Return (Double) Numerator / Denominator;
16 Else
17 Return 1.0;
18 }
19
20 -(Void) Setto: (INT) N Over: (INT) D
21 {
22 Numerator = N;
23 Denominator = D;
24 }
25
26 @ End
Finally, apply it in Main. M:
01 # Import
"Fraction. H"
02
03 Int Main (Int Argc, Const Char * Argv [])
04 {
05 NSAID utoreleasepool * Pool = [[NSAID utoreleasepool Alloc] Init];
06 Fraction * Afraction = [[Fraction Alloc] Init];
07
08 [Afraction Setto: 100 Over: 200];
09 [Afraction Print];
10
11 [Afraction Setto: 1 Over: 3];
12 [Afraction Print];
13 [Afraction Release];
14
15 [Pool Drain];
16 Return 0;
17 }
Example 7-2 is completed. The final output result is as follows:
100/200
1/3
Apple developer Mike Source Code address uploaded on csdn.
