I've written some code that posts data to a MySql database via PHP and the PHP code returns a value of either 'YES' or 'NO' via JSON. I then have an if statement that checks whether it is YES or NO. The if statement works perfectly when I set the 'worked' string manually, but not if I use the data from JSON. I have checked that it is set correctly using NSLog, and I really can't see what the problem could be. Here is a shortened version of my code:
-(void) dataDownloaded {
NSDictionary *theDictionary = [_theArray objectAtIndex:0];
NSString *worked = [theDictionary objectForKey:#"worked"];
NSLog(#"%#", worked);
if (worked == #"NO") {
//code for if it didn't work
} else if (worked == #"YES"){
//code for if it did work
} else {
//code for if it doesn't return either value
}
}
Thanks in advance to anyone who can work out what the problem is!
Your problem is you're using == to compare. That's not going to work. I think you need to read up on Objective-C - try http://www.cocoadevcentral.com/ for that. Here's how you should fix your code:
-(void) dataDownloaded {
NSDictionary *theDictionary = [_theArray objectAtIndex:0];
NSString *worked = [theDictionary objectForKey:#"worked"];
NSLog(#"%#", worked);
if ([worked isEqualToString:#"NO"]) {
//code for if it didn't work
} else if ([worked isEqualToString:#"YES"]){
//code for if it did work
} else {
//code for if it doesn't return either value
}
}
use isEqualToString: for string comparsions
if ([worked isEqualToString:#"NO"]) {
}
Related
I have a code like that
if ([dataArray valueForKey:#"success"]) {
[self.feedsArray addObjectsFromArray:dataArray];
NSLog(#"self.feedsArray: %#",self.feedsArray);
} else {
NSLog(#"no feed found ");
}
dataArray is a NSMutableArray which ultimately contains a JSON Dictionary.
but I am getting the same console output independent of success either TRUE or FALSE, but my console output is always same.my console output is:
for FALSE or NO:
self.feedsArray: (
{
action = register;
message = "Invalid parameters";
success = 0;
}
)
and for TRUE or YES:
self.feedsArray: (
{
action = register;
message = "valid parameters";
success = 1;
}
)
in both cases if part is executed.
in NSUserDefaults there is a method boolForKey but how to do this in case of NSMutableArray.
You need to read the fine print for [NSArray valueForKey:], specifically:
Returns an array containing the results of invoking valueForKey: using
key on each of the array's objects.
and:
The returned array contains NSNull elements for each object that
returns nil.
So if the array contains, say, 3 objects and none of them have a success key then you will get an array of 3 NSNull objects returned.
Therefore the if statement will fire whenever dataArray is non-empty, which is obviously not what you intended.
You should check the contents of the returned array:
BOOL succeeded = NO;
NSArray *results = [dataArray valueForKey:#"success"];
for (NSObject *obj in results) {
succeeded = [obj isKindOfClass:[NSNumber class]] && [(NSNumber *)obj boolValue];
if (succeeded)
break;
}
if (succeeded) {
[self.feedsArray addObjectsFromArray:dataArray];
NSLog(#"self.feedsArray: %#",self.feedsArray);
} else {
NSLog(#"no feed found ");
}
You can do this in simple way:
What i see in your response json value is, you have dictionary in dataArray at index 0
NSMutableDictionary *responseDict = [dataArray objectAtIndex:0];
if([[responseDict objectForKey:#"success"] boolValue])
{
NSLog(#"Success: 1");
}
{
NSLog(#"Success: 0");
}
Use index instead of key for an array.
NSDictionary dictionary = (NSDictionary *)dataArray[0];
if ([(NSNumber *)[dictionary objectForKey:#"success"] boolValue]) {
// ...
}
otherwise use if([[[dataArray objectAtIndex:0] valueForKey:#"success"] isEqualToString:#"1"])
An array does not store keys, the only way to access items in an array is by index.
You should be using an NSDictionary/NSMutableDictionary instead. If you want to use a bool store it as a NSNumber, [NSNumber numberWithBool:YES] and then use the instance method valueForBool to read it back.
Try this
if ([[dataArray valueForKey:#"success"]isEqualToString:#"1"]) {
[self.feedsArray addObjectsFromArray:dataArray];
NSLog(#"self.feedsArray: %#",self.feedsArray);
}
else {
NSLog(#"no feed found ");
}
It 'll work out.
use this if you want bool value
if([[dataArray valueForKey:#"success"] boolValue])
{
//i.e success is true
}
if response contains array of dictionaries then we can use loop and check condition,
here i is index variable of array,
if([[[dataArray objectAtIndex:i] objectForKey:#"success"] boolValue])
{
// success is true ,
}
Replace you code line
if ([dataArray valueForKey:#"success"]) {
}
with
if ([[dataArray valueForKey:#"success"] integerValue]) {
}
Hope it will work for you.
its working with replacing the line with
if ([[[dataArray objectAtIndex:0] valueForKey:#"success"] boolValue])
I'm currently using this HTAutocompleteTextField to fill in a UITextField with a predefined list, should A user start typing in an entry that already exists. There are a couple of problems that I've been having however. The first is that it seems to stop when a comma is typed in (but not apostrophes). I've been looking around and I'm really not sure why it's doing it. I thought at one point it could be that the comma was a different comma, like an apostrophe issue I had due to importing the list from a word document. However, it wasn't the case. The second issue is more of an addition which I'm not really sure how to implement. I also want the autosuggest to detect suggestions for words in mid string, not just from the beginning. So for instance typing in "String" would suggest "This is a String". This currently how it does the auto suggest, but I have no idea how to do the above things.
NSString *prefixLastComponent = [componentsString.lastObject stringByTrimmingCharactersInSet:space];
if (ignoreCase)
{
stringToLookFor = [prefixLastComponent lowercaseString];
}
else
{
stringToLookFor = prefixLastComponent;
}
for (NSString *stringFromReference in colorAutocompleteArray)
{
NSString *stringToCompare;
if (ignoreCase)
{
stringToCompare = [stringFromReference lowercaseString];
}
else
{
stringToCompare = stringFromReference;
}
if ([stringToCompare hasPrefix:stringToLookFor])
{
return [stringFromReference stringByReplacingCharactersInRange:[stringToCompare rangeOfString:stringToLookFor] withString:#""];
}
}
If anyone could give me any pointers on how to get this done, I'd appreciate it.
Regards,
Mike
Managed to go about solving both issues. For any one who uses this Git Repository, the reason why commas don't work when using the preset methods is because of NSArray *componentsString = [prefix componentsSeparatedByString:#","];. Remove the comma so it's NSArray *componentsString = [prefix componentsSeparatedByString:#""]; and it should work nicely. To fix the other problem where it only detects the start of words, I changed the methods a little. Here are my changes in HTAutocompleteManager.m
int i = 0;
for (NSString *stringFromReference in colorAutocompleteArray)
{
NSString *stringToCompare;
if (ignoreCase)
{
stringToCompare = [stringFromReference lowercaseString];
}
else
{
stringToCompare = stringFromReference;
}
if ([stringToCompare hasPrefix:stringToLookFor])
{
//NSLog(#"Removing String: %# atIndex: %d", [colorAutocompleteArray objectAtIndex:i], i);
[colorAutocompleteArray removeObjectAtIndex:i];
[colorAutocompleteArray insertObject:stringFromReference atIndex:0];
//NSLog(#"Adding String atIndex 0: %#", stringFromReference);
return [stringFromReference stringByReplacingCharactersInRange:[stringToCompare rangeOfString:stringToLookFor] withString:#""];
}
else if ([stringToCompare hasSuffix:stringToLookFor] && ([stringToLookFor length] >= 3)) {
return [NSString stringWithFormat:#" %#", stringFromReference];
}
else if (!([stringToCompare rangeOfString:stringToLookFor].location == NSNotFound) && ([stringToLookFor length] >= 3))
{
return [NSString stringWithFormat:#" %#", stringFromReference];
}
++i;
}
The reason for reordering the Array is because after the 3rd character is typed it will prioritise the other two if statements because they will be reached first if there is a generic term in multiple entries in the array (like "Street" in a list of locations). I know it's not necessary to have the "hasSuffix" if statement, but I left it in case someone wants to use it on it's own. Lastly, I added in a space before stringFromReference so that it doesn't look weird when there's a suggestion straight after the input text. When we exit the UITextField we remove this space like this (inside HTAutocompleteTextField.m - commitAutocompleteText):
NSString *currentText = self.text;
if ([self.autocompleteString isEqualToString:#""] == NO
&& self.autocompleteDisabled == NO)
{
if ([self.autocompleteString hasPrefix:#" "]) {
self.autocompleteString = [self.autocompleteString substringFromIndex:1];
}
self.text = [NSString stringWithFormat:#"%#", self.autocompleteString];
self.autocompleteString = #"";
[self updateAutocompleteLabel];
}
return ![currentText isEqualToString:self.text];
Hope this makes sense to anyone who's in a similar situation.
Mike
for(NSDictionary *feed in Feeds)
{
NSString *feedName=[feed objectForKey:#"name"];
if(listofBusiness==nil)
{
listofBusiness=[[NSMutableArray alloc]init];
}
if([listofBusiness indexOfObject:feedName] !=NSNotFound)
{
[listofBusiness addObject:feedName];
[feedName release];
feedName=nil;
}
}
in this code when compiler comes on this statement
if([listofBusiness indexOfObject:feedName] !=NSNotFound)
then not go into codition and go to increment in for loop so that any element is not added in array.what is error in this code?
The logic appears to be inverted - you probably want it to add the elemement when
[listofBusiness indexOfObject:feedName] == NSNotFound
But at the moment you have the opposite - you only try to add the object when it is 'not not found' - i.e. when it is already present in the list.
indexOfObject is not working for an array
Try with containsObject method of an array.
Example :
if([listofBusiness containsObject:feedName]) {
// your code
}
hey all, i'm trying to read a file on the web that says "this is a test" and i wanna compare it... so here's what i got:
NSError *error;
NSURL *theURL = [NSURL URLWithString:#"http://mysite.com/test.asp"];
NSString *test = [NSString stringWithContentsOfURL:theURL encoding:NSASCIIStringEncoding error:&error];
NSLog(#"%#",test); //prints the results.. .does work
if(test == "this is a test"){
NSLog(#"File read");
} else {
NSLog(#"Bad file");
}
What am i doing wrong here? I always get "Bad file" but i know it's pulling in the text. Thanks all
damien
You need to check for nil as well & use isEqualToString function for comparison.
if(test != nil){
if([test isEqualToString:#"this is a test"]) {
// equal
}
else{
// not equal
}
}
else{
NSLog(#"Bad file");
}
If you use ==, you'll be comparing two pointers. Use isEqual: like so:
if([test isEqual: #"this is a test"]) {
// equal
}else{
// not equal
}
Other than the 2 answer you can also use.
– caseInsensitiveCompare:
– localizedCaseInsensitiveCompare:
– compare:
– localizedCompare:
– compare:options:
– compare:options:range:
– compare:options:range:locale:
– localizedStandardCompare:
I'm new in objective-c, this is my first post. This is my problem:
In my main file I have a variable: NSString *var;
Then I have a function:
-(BOOL) myfunction:(NSString *)myvar {
myvar = #"OK!";
return YES;
}
Now in the main file I do:
NSString *var;
BOOL control = myfunction:var;
if(control)
NSLog(#"var is: %#",var);
but the output is "var is: ". If I built in debug mode, and put a breakpoint at the start of function myfunction the memory address of myvar is equal to var, but after the assignment the address of myvar is different from the address of var. How can I solve it? thanks in advance!
While the answers given so far are correct. I think a more pertinent question is why you would want to do this.
It looks you want to have a defensive programming style where the return code indicates success or failure.
A more Objective-C like way to do this would be to pass the string and an NSError ** as a parameter and return the string or a nil to indicate failure as described in the Error Handling Programming Guide
So the way to write this would be:
- (NSString *)aStringWithError:(NSError **)outError {
returnString = #"OK";
if (!returnString) {
if (outError != NULL) {
NSString *myErrorDomain = #"com.company.app.errors";
NSInteger errNo = 1;
*outError = [[[NSError alloc] initWithDomain:myErrorDomain code:errNo userInfo:nil] autorelease];
}
}
return returnString;
}
And to use it:
NSError *error;
NSString *stringVariable = [self aStringWithError:&error];
if (!stringVariable) {
// The function failed, so it returned nil and the error details are in the error variable
NSLog(#"Call failed with error: %ld", [error code]);
}
This is a trivial example, but you can see that you can construct and return far more meaningful information about the error rather than just whether it succeeded or not.
You can also use NSMutableString.
-(BOOL) myfunction:(NSMutableString *)myvar {
[myvar setString:#"OK!"];
return YES;
}
and change your call site as follows:
NSMutableString *var = [NSMutableString string];
BOOL control = [self myfunction:var];
if(control)
NSLog(#"var is: %#",var);
Syntactically you need to fix your myFunction invocation like so:
BOOL control = [self myfunction:var];
The real problem here is that inside of myFunction you are assigning a string value to a local string variable only, whereas you want to change the underlying string that it points to. This is usually the wrong approach in Obj-C, but you can do it like so:
-(BOOL)myfunction:(NSString **)myvar
{
*myvar = #"OK!";
return YES;
}
NSString *var;
BOOL control = [self myfunction:&var];
if(control)
NSLog(#"var is: %#",var);