My string comparison keeps returning false and I dont understand why. Even my nslog says the value is correct. Do you know why my comparison keeps returning false even though the strings appear to be the same? If I step through the program type shows SV as its value. I have ensured there are no spaces in this string as well. We get the first two chars of this:
SV2B799E5B-4306-4965-B5DD-944D3970E6B6
NSString *fPath = [path stringByAppendingPathComponent:[directoryContent objectAtIndex:x]];
NSString *fName = [directoryContent objectAtIndex:x];
NSString *type = [fName substringToIndex:2];
NSLog(#"TYPE: %#",type);
if ([type caseInsensitiveCompare:#"SV"])
{
NSData *file = [[NSData alloc] initWithContentsOfFile:fPath];
if (file)
{
[[WebService sharedWebService]saveVolunteer:nil :YES :[directoryContent objectAtIndex:x] :file];
[file release];
}
}
[NSString -caseInsensitiveCompare:] does not return a BOOL, it returns an NSComparisonResult. This is going to be 0 if the strings are equal (in a case insensitive fashion), which is why you're seeing that result.
Invert your result and you'll be set, or to be more correct, check to see if it is == NSOrderedSame.
The method you are calling returns an NSComparisonResult, not a boolean value. It so happens that an NSComparisonResult of equal has the value zero, which is interpreted as false.
caseInsensitiveCompare: returns a NSComparisonResult. Try [type caseInsensitiveCompare:#"SV"] == NSOrderedSame
Related
I am writing code in objective-c. I would like to extract a url from a string.
Here is my code:
NSMutableString *oneContent = [[latestPosts objectAtIndex:i] objectForKey:#"content"];
NSLog(#"%#", oneContent);//no problem
NSString *string = #"http";
if ([oneContent rangeOfString:string].location == NSNotFound) {
NSLog(#"string does not contain substring");
} else {
NSLog(#"string contains substring!");
}
As you can see, I want to extract a url from the oneContent string, and I have checked that oneContent definitely contains "http", but why does the result show nothing?
Is there some better way to extract the url?
Check oneContent or the actual code you are running.
This works:
NSMutableString *oneContent = [#"asdhttpqwe" mutableCopy];
NSLog(#"%#", oneContent);//no problem
NSString *string = #"http";
if ([oneContent rangeOfString:string].location == NSNotFound) {
NSLog(#"string does not contain substring");
} else {
NSLog(#"string contains substring!");
}
NSLog output:
Untitled[5911:707] asdhttpqwe
Untitled[5911:707] string contains substring!
It is probably best not to use a Mutable string unless there is some substantial reason to do so.
I would suggest using NSScanner.
When I check the value of number in nslog it shows '0'
NSMutableDictionary *data = [[NSMutableDictionary alloc] initWithContentsOfFile: path];
NSNumber *number=[data objectForKey:#"serial"];
NSLog(#"%#",number);
if(number ==0 )
{
imgButton.hidden=YES;
}
But the condition always fails , I also changed the code like this
NSString *number=[data objectForKey:#"serial"]
NSLog(#"%#",number);
if(number == #"0" )
{
imgButton.hidden=YES;
}
But here too the condition fail ,What is the issue with this?
In the first code you are checking a NSNumber, object, against an int.
The correct check is:
if([number intValue] == 0) {
imgButton.hidden = YES;
}
In the second code you are checking two NSString, but you have to use the "isEqualToString" method and not "==". The correct code is:
if([number isEqualToString:#"0"]) {
imgButton.hidden = YES;
}
NSNumber is an object, 0 is an integer (a primitive type). They will never be equal. But you can change the comparison like this [number intValue] == 0 and this will work when the value of your NSNumber is 0.
On the string comparison, you should use the method
isEqualToString:NSString *)string
for the comparison.
For NSNumbers its
isEqualToNumber:(NSNumber *)number
Because otherwise you arent comparing if they have the same value, but if they are stored in identical memory space.
This is my code:
NSString * atime = [NSString stringWithFormat:#"%#",[theDataObject.minuteArray objectAtIndex:indexPath.row]];
NSLog(#"value of atime is:%#",atime);
if (atime==#"0") {
NSString * timeStr = [NSString stringWithFormat:#"%#s",[theDataObject.secondArray objectAtIndex:indexPath.row]];
cell.timeLabel.text = timeStr;
}
else {
NSString * timeStr = [NSString stringWithFormat:#"%#m%#s",[theDataObject.minuteArray objectAtIndex:indexPath.row],[theDataObject.secondArray objectAtIndex:indexPath.row]];
cell.timeLabel.text = timeStr;
}
But it never return first statement only return second statement,even is atim value is 0.
log value:
MyAudioRecorder[2484:10703] value of atime is:0
also tried to put 0 instead of #"0",still does not work.
if (atime==#"0")
Compares the memory address of atime with the address of constant string #"0".
if ([atime isEqualToString:#"0"])
Compares the values that are stored in the two memory locations.
From your requirement it is seen that you want to compare the value not the memory location. So go for 2nd one.
Try the following:
if ([atime isEqualToString : #" "]) {}
isEqualToString: ->
- (BOOL)isEqualToString:(NSString *)aString
Returns a Boolean value that indicates whether a given string is equal to the receiver using a literal Unicode-based comparison.
Discussion -> When this method compares two strings, if the individual Unicodes are the same, then the strings are equal
For more you can access apple NSString Class Reference
if([atime isEqualToString:#"0"])
{
}
else
{
}
I'm sure this is really basic but I can't see what I'm doing wrong. Can someone help me understand where I'm going wrong please? I'm working in xcode. I'm trying to make different parts of my view appear depending on values saved in a property list. If the value assigned to a particular UITextField is equal to zero then I want to hide that UITextField. I'm trying to do this like this. gross is the name of a UITextField:
NSArray *array = [[NSArray alloc] initWithContentsOfFile:filePath];
gross.text = [array objectAtIndex:7];
if ([array objectAtIndex:7 == 0]) {
gross.hidden = YES;
}
else {
gross.hidden = NO;
}
[array release];
I think the problem is something to do with how I've wrote the if/else statement. I know this is really basic but I don't quite understand where I'm going wrong. So Your help is much appreciated.
Code should read:
NSArray *array = [[NSArray alloc] initWithContentsOfFile:filePath];
gross.text = [array objectAtIndex:7];
if ([[array objectAtIndex:7] isEqualToString:#"0"]) {
gross.hidden = YES;
} else {
gross.hidden = NO;
}
[array release];
This assumes that the object at index 7 of your array exists and is a string. If it's actually an NSNumber, then you should instead use the conditional
if ([[array objectAtIndex:7] intValue] == 0) {
Note the above line works for a string where the text contains an int, such as #"0" or #"7".
if ([[array objectAtIndex:7] intValue] == 0)
First mistake is position of closing ]. And second one is you probably have NSString in array, as you have assigned that in text property. So you need to convert it to int by using intValue.
If your array contains nsstring then your condition should look like:
if ([[array objectAtIndex:7] intValue] == 0) {
...
or
if ([[array objectAtIndex:7] isEqualToString:#"0"]) {
1st condition will work also if your array contains NSNumbers (not likely in your case as you assign array elements to text property), but will fail if string is not a valid number - in that case intValue will return 0 as well.
2nd condition will work fine if you're sure that your elements are strings and you want to compare exactly with #"0".
Your condition is equivalent to
if ([array objectAtIndex:0])
because == operator has greater priority and evaluates to 0. Comparing array's element to 0 directly also does not make sense as NSArray cannot contain nil objects anyway
It might be easier to get the length of the array first and make sure that it has enough elements and then start accessing the elements themselves.
I'm getting this warning "Format not a string literal and no format arguments? Any ideas?
-(BOOL)isFirstPointReached{
NSString *firstPoint = [NSString stringWithFormat:[pointsToFillArray objectAtIndex:0]];
NSString *lastPoint = [NSString stringWithFormat:[pointsToFillArray lastObject]];
if([firstPoint isEqualToString:lastPoint]){
return YES;
}
else{
return NO;
}
}
A few points...
The pointsToFillArray is an array of objects and the compiler does not know if it contains NSStrings or any other type of object. To get rid of the error you would cast it to (NSString*)
Secondly, the stringWithFormat is normally used to create a string from a few different pieces of data and does not need to be used in this case
Thirdly, you could just create pointers to the objects within the array and then do your check
The following should work for you:
NSString *firstPoint = (NSString*)[pointsToFillArray objectAtIndex:0];
NSString *lastPoint = (NSString*)[pointsToFillArray lastObject];
if ([firstPoint isEqualToString:lastPoint]) {
return YES;
}