I've google and i can't find the exact closest thing to the function i'm seeking.
So this is the idea of the generating message on the iOS apps.
This just randomly generate random number depend on the length
// Generates alpha-numeric-random string
- (NSString *)genRandStringLength:(int)len {
static NSString *letters = #"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
NSMutableString *randomString = [NSMutableString stringWithCapacity: len];
for (int i=0; i<len; i++) {
[randomString appendFormat: #"%C", [letters characterAtIndex: arc4random() % [letters length]]];
}
return randomString;
}
What i'm seeking is for the apps to generate random messages store in the array list depending on the settled time.
This is how i want it to work
static NSString *letters = #"Hello all","You're awesome","This is awkward","Are you sleeping?";
I need help to generate random messages in the string of arrays . Thank you in advance
This is not a way of doing this certain task. you have to make one array with most of word instad of punting single string with all alphabet character And create random sentence. This is logical and programmatic task xcode not generate random word it self. you have to do some logical stuff your self.
Here i found one github example code please check Bellow you got idea how does you can achieve this task. Hope you getting some idea with this example.
https://github.com/dav/Objective-C-Lorem-Ipsum-Generator
Related
for(int i=0;i<[serviceNamesFilterArray count];i++){
NSLog(#"state : %#", [serviceNamesFilterArray objectAtIndex:i]);
NSString *str = [serviceNamesFilterArray objectAtIndex:i];
if (tag_id == [serviceNamesFilterArray indexOfObject:str] ) {
// filterButtonArray = serviceNamesFilterArray;
[filterButtonArray addObject:str];
NSLog(#"%#",filterButtonArray);
}
}
I want to access index of serviceNamesFilterArray. How can i access index's of my array so that i can compare it with integer tag_id?
Even Objective-C provides smarter filter APIs than a loop.
index will contain the index of the object in the array matching tag_id
NSInteger index = [self.serviceNamesFilterArray indexOfObjectPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop) {
return (NSString *)obj.integerValue == tag_id;
}];
you can compare i value with your tag_id as follows:
for(int i=0;i<[serviceNamesFilterArray count];i++) {
NSLog(#"state : %#", [serviceNamesFilterArray objectAtIndex:i]);
NSString *str = [serviceNamesFilterArray objectAtIndex:i];
if (tag_id == i) {
//perform your logic here
}
}
you can use the enumerateObjectsUsingBlock method, like
[serviceNamesFilterArray enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
// ...
}];
Preamble: you are using [array objectAtIndex:index] in your code, while this was the way to index historically in modern Objective-C you simply write array[index]. If you are learning Obj-C from a book/website you might want to look for a newer text.
It is unclear what you are asking let’s see what we can figure out.
You start with a loop:
for(int i=0;i<[serviceNamesFilterArray count];i++)
Here i is going to be used as an index into the array serviceNamesFilterArray. Inside the loop you then access the object at index i (updating your code as above):
NSString *str = serviceNamesFilterArray[i];
and having obtained the object at index i you ask what is the index of that object:
[serviceNamesFilterArray indexOfObject:str]
There are two possible answer here:
i – this is the most obvious answer and will be the result if there are no duplicates in serviceNamesFilterArray. It will be the answer as you just obtained str from index i of the array.
j where j < i – this will be the answer if the array contains duplicates and the same string is found at indices j and i. This result happens because indexOfObject: returns the first index at which the object occurs with the array.
The most likely result seems to be (1) in your case (guessing you do not have duplicate “service names”). In this case your conditional is equivalent to:
if (tag_id == i) {
[filterButtonArray addObject:str];
}
However if this is your intention then the loop is completely unnecessary as your code is equivalent to:
NSString *str = serviceNamesFilterArray[tag_id];
[filterButtonArray addObject:str];
If the serviceNamesFilterArray does contain duplicates then your code as written may add the string at index tag_id multiple times to filterButtonArray or it may add it no times – we'll leave figuring out why as an exercise, and we doubt this is your intention anyway.
At the time of writing #vadian has made a different guess as to your aim. Their solution finds the index, if any, where the string value if interpreted as an integer is equal to the value of tag_id (an integer). If that is your aim then #vadian’s solution provides it.
Of course both our and #vadian’s guesses might be wrong at to what your aim is. If so you can edit the question to explain, or delete it and ask a new one instead – given this question has at the time of writing 3 answers already deletion in this case might be better to reduce future confusion when people read the (revised) question and (outdated) answers.
HTH
Maybe you just need to judge whether the tag_id is less than count of serviceNamesFilterArray, then you can get the value by tag_id directlly.
if (tag_id < [serviceNamesFilterArray count]){
NSString *str = [serviceNamesFilterArray objectAtIndex:tag_id];
// other logic here
}
I have an iOS application that talks to a RedBearLab Arduino device. My code that I use to send an int via bluetooth from Arduino to iOS is as follows:
void sendMyInt(int myInt) {
char b[4];
String str;
str=String(myInt);
str.toCharArray(b,4);
for (int i; i < 3; i++) {
char toPrint = b[i];
ble_write(toPrint);
}
}
Here is my code on the receiving end:
-(void) bleDidReceiveData:(unsigned char *)data length:(int)length
{
NSData *d = [NSData dataWithBytes:data length:length];
NSLog([NSString stringWithFormat:#"%#",d]);
NSString *s = [[NSString alloc] initWithData:d encoding:NSUTF8StringEncoding];
const char* clearChar = "!";
if ([self.label.text isEqualToString:#"Label"]) {
self.label.text = #"";
}
else if ([s isEqualToString:[NSString stringWithUTF8String:clearChar]]) {
self.label.text = #"";
}
else {
NSString *store = self.label.text;
NSString *full = [NSString stringWithFormat:#"%#%#",store,s];
self.label.text = full;
}
}
The final else statement fires somewhat as expected, and a value of 233! is printed out to the label over and over again, getting longer each time eventually forming things like 233!233!233! etc. As you can see, I am using a character (!) sent over a function to clear the label, but it never clears. The integer is the ASCII code for the exclamation point:
void clearLabel() {
int clearString = 33;
char excalamtion = clearString;
ble_write(excalamtion);
}
Why would this not clear the label? I assume it has something to do with the clashing formats, but I'm not really too good at that even after reading some documentation. For the else if statement I also tried this
if ([s isEqualToString:#"!"])
but that didn't work out either... Any help would be appreciated.
EDIT:
I forgot to put in my loop code so you can see function calls. Here it is:
void loop()
{
if ( ble_connected() ) {
int a = 223;
sendMyInt(a);
delay(1000);
clearLabel();
delay(1000);
}
ble_do_events();
}
EDIT 2:
Based on a suggestion by #Duncan C , I have isolated the problem to the fact that the data is being sent as one packet to the iPhone. Upon printing out my generated string when the data is received, the string 233! is received all at once rather than individual chars of 2 3 3, and one second later the signal to clear, !. The data takes two seconds to appear on my phone, indicating that both delays are being used. I need a way to separate the 2 3 3 packet from the ! packet.
First off, this line:
NSLog([NSString stringWithFormat:#"%#",d]);
Is sort of pointless. The stringWithFormat serves no real purpose, since NSLog takes a format string anyway.
Use this instead:
NSLog(#"%#", d);
You should probably also log the contents of "s" once you convert your NSData to an NSString. That will help you figure out what's going on.
What is likely going on is that your string is coming in as "233!", all together, 4 bytes at a time (assuming that your integer is == 233).
Your string is unlikely to ever contain just "!". Instead, it will likely contain "233!" (4 characters.) I say likely because it depends on how the data is packetized into BLE. Something that short should be sent all in 1 BLE packet, so you should get the entire string together.
You could use the NSString method rangeOfString: to search for your "!" string, and if it contains an "!", clear your label, but that won't really do any good either. If you're sending "233!", then the iOS code will see the exclamation point in the string it receives and simply clear the label.
Or does your arduino project first send "233", then after some other event, send the "!". You didn't make that clear.
Another problem: What does the Arduino String class do if the integer is less than 1000, or less than 100, and doesn't require 3 or 4 characters to convert to a char array? What is stored in the unused bytes? You're always sending 4 characters, which is probably wrong.
Adding in another ble_do_events(); after calling the sendMyInt(); function causes the data to be transmit in two separate packets.
I am making a program where I need to loop through an array with a list of letters. I want the letters to be shown on their specific label. I have therefore created an outlet of each (about 38) and given them the name "alif01", "alif02", etc.
for (int i = 0; i < [arabicLetters count]; i++) {
int num = i;
NSString *letterString = [arabicLetters objectAtIndex:i];
NSLog(#"alif0%d is %#", num, letterString);
alif0**[i]**.text = arabicLetters[i];
}
is it possible to use the index [i] instead of writing it all manually?
You should not have 38 IBOutlet properties for this. You should have an array (possibly an IBOutletCollection) so that you can loop over the array / index into the array.
While technically you can create a key name and use KVC valueForKey: (appending strings / string format), the array approach is a much better solution.
Indeed, as you already have a loop, you would be better served by creating the labels in the loop directly, then you know you have the correct number. This is particularly beneficial later, when you change the contents of arabicLetters (though that sounds like it isn't a concern in this particular case).
Try with below code:
for (int i = 0; i < [arabicLetters count]; i++) {
NSString *letterString = [arabicLetters objectAtIndex:i];
NSString *propertyName = [NSString stringWithFormat:#"alif0%d.text",i];
[self setValue:letterString forKeyPath:propertyName];
}
Please bear with me. I am new to C altogether, let alone Objective C. I am trying to do something that should be simple however its not working. I am scanning a string of numbers that also contains symbols. As the mini function runs through the input string it appends numbers to a new string until it comes across an operator (I'm writing a calculator in my own way as a learning exercise.) Right now I am just doing the beginning part and scanning the string and appending character. Here is my code:
char userInput[99];
NSMutableString *number = nil;
int i;
printf( "Please enter math: " );
scanf( "%s", userInput );
fpurge( stdin );
NSString *InputString = [NSString stringWithUTF8String:userInput];
for (i=0; i < [InputString length]; i++) {
char current = [InputString characterAtIndex:i];
if (isalnum(current)) {
[number appendString:[NSString stringWithCharacters:¤t length:1]];
NSLog(#"%# ", number);
}
}
For the life of me I can not seem to figure out why it keeps printing 2012-05-02 19:23:20.935 CALC[1447:403] (null) instead of the number value for each number it comes across. So for example if there are 5 numbers in the entered string it will print that 5 times.
You never initialized number--so when you call -appendString: on it, you're only appending to nil, and the result is just nil back. Try this for your second line:
NSMutableString *number = [NSMutableString string];
Now number is an empty string object, which is very different from being nil, which is no object at all.
I have a binary file I've loaded using an NSData object. Is there a way to locate a sequence of characters, 'abcd' for example, within that binary data and return the offset without converting the entire file to a string? Seems like it should be a simple answer, but I'm not sure how to do it. Any ideas?
I'm doing this on iOS 3 so I don't have -rangeOfData:options:range: available.
I'm going to award this one to Sixteen Otto for suggesting strstr. I went and found the source code for the C function strstr and rewrote it to work on a fixed length Byte array--which incidentally is different from a char array as it is not null terminated. Here is the code I ended up with:
- (Byte*)offsetOfBytes:(Byte*)bytes inBuffer:(const Byte*)buffer ofLength:(int)len;
{
Byte *cp = bytes;
Byte *s1, *s2;
if ( !*buffer )
return bytes;
int i = 0;
for (i=0; i < len; ++i)
{
s1 = cp;
s2 = (Byte*)buffer;
while ( *s1 && *s2 && !(*s1-*s2) )
s1++, s2++;
if (!*s2)
return cp;
cp++;
}
return NULL;
}
This returns a pointer to the first occurrence of bytes, the thing I'm looking for, in buffer, the byte array that should contain bytes.
I call it like this:
// data is the NSData object
const Byte *bytes = [data bytes];
Byte* index = [self offsetOfBytes:tag inBuffer:bytes ofLength:[data length]];
Convert your substring to an NSData object, and search for those bytes in the larger NSData using rangeOfData:options:range:. Make sure that the string encodings match!
On iPhone, where that isn't available, you may have to do this yourself. The C function strstr() will give you a pointer to the first occurrence of a pattern within the buffer (as long as neither contain nulls!), but not the index. Here's a function that should do the job (but no promises, since I haven't tried actually running it...):
- (NSUInteger)indexOfData:(NSData*)needle inData:(NSData*)haystack
{
const void* needleBytes = [needle bytes];
const void* haystackBytes = [haystack bytes];
// walk the length of the buffer, looking for a byte that matches the start
// of the pattern; we can skip (|needle|-1) bytes at the end, since we can't
// have a match that's shorter than needle itself
for (NSUInteger i=0; i < [haystack length]-[needle length]+1; i++)
{
// walk needle's bytes while they still match the bytes of haystack
// starting at i; if we walk off the end of needle, we found a match
NSUInteger j=0;
while (j < [needle length] && needleBytes[j] == haystackBytes[i+j])
{
j++;
}
if (j == [needle length])
{
return i;
}
}
return NSNotFound;
}
This runs in something like O(nm), where n is the buffer length, and m is the size of the substring. It's written to work with NSData for two reasons: 1) that's what you seem to have in hand, and 2) those objects already encapsulate both the actual bytes, and the length of the buffer.
If you're using Snow Leopard, a convenient way is the new -rangeOfData:options:range: method in NSData that returns the range of the first occurrence of a piece of data. Otherwise, you can access the NSData's contents yourself using its -bytes method to perform your own search.
I had the same problem.
I solved it doing the other way round, compared to the suggestions.
first, I reformat the data (assume your NSData is stored in var rawFile) with:
NSString *ascii = [[NSString alloc] initWithData:rawFile encoding:NSAsciiStringEncoding];
Now, you can easily do string searches like 'abcd' or whatever you want using the NSScanner class and passing the ascii string to the scanner. Maybe this is not really efficient, but it works until the -rangeOfData method will be available for iPhone also.