I am trying to make my code run, but it always stops.
Can someone of you help me solve the problem.
For some reason it wont accept this.
-(Animal *) getAnimalAt:(int)input {
//NSLog(#"show input %ld", input);
Animal *ani = [animals objectAtIndex:input];
return ani;
}
I call this method in my main by :
for(int i=0;i< count;i++){
Animal *ani = [farm getAnimalAt:i];
NSLog(#"ani : %#",[ani makeSound]);
NSLog(#"ani : %#",[ani doFly]);
}
If you need any more info or code please ask.
Also do any of you have found a good tutorial? I cant seem to find one?
Or a site like codingbat would be very helpfull.
If animals is just an NSArray you could remove the getAnimalAt: method and just use the NSArray. Then you could do something like:
for (Animal *ani in animals) {
NSLog(#"ani : %#", [ani makeSound]);
NSLog(#"ani : %#", [ani doFly]);
}
which will prevent any problems with count being greater than the number of elements in animals
Related
So today I went back to coding after a while (half a year? plus before it wasn't like I was any good lol ...) and wanted to pickup Swift but this stopped me just before I even gave it a good try:
BTW I'm trying to make a "myWorld" variable that would act as the scene handler later on, well, u get the idea......
http://postimg.org/image/4n1izokcj/
(the error can't be seen here on stackoverflow, little resolution upload...)
the old Obj-C way that worked for me for initialising a new SKNode:
#interface Level() {
SKNode* myWorld;
}
#implementation Level
-void setUpScene {
myWorld = [SKNode node]
[self addChild:myWorld]
}
the new Swift way that I thought should work:
var myWorld:SKNode?
class Level:SKScene {
func setUpScene() {
myWorld = SKNode.node()
self.addChild(myWorld!)
}
}
what am I doing wrong? (the "myWorld! = SKNode.node()" does the same...)
pls no flame.
thx for any constructive reply ^__^
OK, I'm just blind... the syntax is
myWorld = SKNode()
& not
myWorld = SKNode.node()
jeez... feel free to erase this question editors...
EDIT: The issue was with the assert as people pointed out below. Thanks for the help!
I have a enum set that i'm trying equate, but for some reason its not working.
Its declared like so:
typedef NS_ENUM(NSUInteger, ExUnitTypes) {
kuNilWorkUnit,
kuDistanceInMeters,
//end
kuUndefined
};
And i'm using it here:
+(NSString*) ExUnitDescription: (ExUnitTypes) exUnit
{
if (exUnit == kuNilWorkUnit)
{
assert("error with units");
}
///.... more stuff
}
Xcode isnt triggering my assert. EDIT: the assert is just for testing. i've used NSLog as well. The conditional isn't evaluating to true even though the value is clearly kuNilWorkUnit.
Does anyone have any suggestions or ideas of what i'm doing wrong?
You want to do this:
+(NSString*) ExUnitDescription: (ExUnitTypes) exUnit
{
assert(exUnit != kuNilWorkUnit);
///.... more stuff
}
This is because, assert only stops execution if the expression you pass to it is false. Since a string literal is always non-zero, it will never stop execution.
Now, since you are using Objective C and it also looks like you want to have a message associated with your assert, NSAssert would be preferable.
+(NSString*) ExUnitDescription: (ExUnitTypes) exUnit
{
NSAssert(exUnit != kuNilWorkUnit, #"error with units");
///.... more stuff
}
I have two objective c methods. One needs to return an int[][] and the other which needs to take int[][] as a parameter. I was originally using an NSMutableArray with NSMutableArrays as values however I was told to redo it like this in order to be compatible with some current code. I can't figure out how to make this work. I'm not sure I'm even googling the right thing. Anyway here is what I have now.
+(int [][consantValue]) getCoefficients
{
int coefficiennts [constantValue2][constantValue1] = { {0,1,2}, {3,4,5}, {6,7,8} };
return coefficients;
}
At the return statement I get the Error "Array initilizer must be an initializer list'
I also have to take the int[][] and rebuild it into an NSMutableArray of NSMutableArrays in another method but I'm hoping if someone can give me a hint on the first part I can work the second part out myself although if anyone has any advice on that I would appreciate it as well. Thanks.
The easy way to do this for fixed size array(s) is to use a struct for storage:
typedef struct {
int at[constantValue2][constantValue1];
} t_mon_coefficients;
And then you'd declare the method which returns by value:
+ (t_mon_coefficients)coefficients;
And passes by value as a parameter:
- (void)setCoefficients:(const t_mon_coefficients)pCoefficients;
If the struct is large, you should pass by reference:
// you'd use this like:
// t_mon_coefficients coef;
// [SomeClass getCoefficients:&coef];
+ (void)getCoefficients:(t_mon_coefficients* const)pOutCoefficients;
- (void)setCoefficients:(const t_mon_coefficients*)pCoefficients;
But there are multiple ways one could accomplish this.
I've been stuck with this problem from a couple of days and I can't get myself out of it.
I've searched all over the net, but I couldn't find anything useful to solve my issue.
this is the scenario.
I've got an array of strings containing a bunch of ids fetched from a coredata sqlite db and
I'd like to know the index of a certain element into this array.
My first solution would have been as easy as using indexOfObject
-(NSInteger) getPageId:(NSString *)symbol_id {
NSInteger refId = [myIds indexOfObject:symbol_id];
// .. stuff ..
return refId;
}
now, I don't know why, but the returning value of the function is always NSNotFound.
If I print out the values via NSLog
NSLog(#"%#\n%#", myIds, symbol_id);
I can clearly see that the value I'm searching for figures out into the elements of the array.
I've even tried a dumbest solution, like probing the match via isEqual function into a for loop:
int idx = 0;
for(NSString *tok in myIds) {
if([tok isEqual:synmbol_id])
{
NSLog(#"yay, a match was encountered!!");
return idx;
}
idx++;
}
but the execution never gets into the NSLog.
I dunno where to knock my head.
hope that some of you already figured this out and could explain this to me.
thx in advance
k
Try printing all the elements on the array like this:
for(NSString *tok in myIds) {
NSLog(#"On the array [%#]", tok);
}
Maybe there is a TAB \t, an ENTER \n or something weird in your NSString preventing isEqual message to run as expected. Usually these characters are hard to find on a regular debugger. That's why I'am suggesting to enclose the string in [].
I'm trying something like my first comparison App in Obj-C and i'm already running into trouble.
Well, there is a textBox with unamebox:(id)unb and a textfield NSTextField* myOut;
Well, here was my first try:
if ([unb stringValue] == #"hello") {
[myOut setStringValue:(NSString *)#"hello dude"];
}
else {
[myOut setStringValue:(NSString *)#"What?"];
}
To my shame, this always setzt the text field to "What?"
When I try the isEqualtoString, it doesn't even do anything:
if ([unb isEqualToString:(NSString*)#"hello"]) {
[myOut setStringValue:(NSString *)#"hello dude"];
}
else {
[myOut setStringValue:(NSString *)#"What?"];
}
So, what shall I do to compare it?
by the way, I already read the links which were suggested above. If I missed anything important, I'm sorry
-isEqualToString: is a method on an NSString, not on an NSTextField. You should be getting an error from sending that message.
You want this:
[[unb stringValue] isEqualToString:#"hello"]