I am writing some code to allow users to answer multiple choice questions. So I have an NSArray of values [#"value1", #"value2", ..]
I want to display them as:
A) value1
B) value2
The code I have is
for(int i = i; i < [values count]; i = i+1) {
NSString *displayValue = [[NSString alloc] initWithString:<NEED HELP HERE>];
displayValue = [displayValue stringByAppendingString:#") "];
displayValue = [displayValue stringByAppendingString:[values objectAtIndex:i];
}
The question I have is if there is where I have put , how could I convert i to the right ASCII character (A, B, C, etc) and initialize the string with that value
NSString *displayValue = [NSString stringWithFormat:#"%c",'A'-1+i];
and to get the whole string at once, use:
NSString *displayValue = [NSString stringWithFormat:#"%c) %#",'A'-1+i,
[values objectAtIndex:i]];
(ps. if you alloc an object, you must also release or autorelease, or you will "leak" memory)
Look at NSString:initWithFormat method, along with the String Programming Guide.
Related
I want to create a comma-separated string like this.
NSString *list = #"iPhone,iPad,iPod";
I tried like this,
[strItemList appendString:[NSString stringWithFormat:#"%#,", [[arrItems objectAtIndex:i]objectForKey:#"ItemList"]]];
But the issue is I'm getting a string like this
#"iPhone,iPad,iPod," Note that there is an extra comma "," at the end of the string. How can I avoid that extra comma?
Can you please give me a hint. Highly appreciated
Thanks in advance
To join an array of strings into a single string by a separator (character which would be a string), you could use this method of NSArray class:
NSArray* array = #[#"iPhone", #"iPad", #"iPod"];
NSString* query = [array componentsJoinedByString:#","];
By using this method, you won't need to drop the last extra comma (or whatever) because it won't add it to the final string.
There's a couple of routes you can take.
If the number of items is always the same, and known before hand (which I guess isn't the case, but I mention it for completeness's sake), just make the whole string at once:
[NSString stringWithFormat:#"%#,%#,%#", [[arrItems objectAtIndex:0] objectForKey:#"ItemList"]], [[arrItems objectAtIndex:1] objectForKey:#"ItemList"]], [[arrItems objectAtIndex:2] objectForKey:#"ItemList"]]
Knowing that the unwanted comma will always be the last character in the string, you can make removing it the last step in construction:
} // End of loop
[strItemList removeCharactersInRange:(NSRange){[strItemList length] - 1, 1}];
Or you can change your thinking a little and do the loop like this:
NSString * comma = #"";
for( i = 0; i < [arrItems count]; i++ ){
[strItemList appendString:[NSString stringWithFormat:#"%#%#", comma, [[arrItems objectAtIndex:i]objectForKey:#"ItemList"]]];
comma = #",";
}
Notice that comma comes before the other item. Setting that string inside the loop means that nothing will be added on the first item, but a comma character will be for every other item.
After Completion of loop add below stmt
strItemList = [strItemList substringToIndex:[strItemList length]-1]
check the value of array count if array count is last then add without comma else add with comma. try this out i am not sure to much about.
if([arrItems objectAtIndex:i] == arrItems.count){
[strItemList appendString:[NSString stringWithFormat:#"%#", [[arrItems objectAtIndex:i]objectForKey:#"ItemList"]]];
}
else {
[strItemList appendString:[NSString stringWithFormat:#"%#,", [[arrItems objectAtIndex:i]objectForKey:#"ItemList"]]];
}
Assuming that arrItems is an NSArray with elements #"iPhone", #"iPad", and #"iPod", you can do this:
NSArray *list = [arrItems componentsJoinedByString:#","]
NSArray with elements #"iPhone", #"iPad", and #"iPod"
NSString *str=[[arrItems objectAtIndex:0]objectForKey:#"ItemList"]]
str = [str stringByAppendingFormat:#",%#",[[arrItems objectAtIndex:1]objectForKey:#"ItemList"]]];
str = [str stringByAppendingFormat:#",%#",[[arrItems objectAtIndex:2]objectForKey:#"ItemList"]]];
NsLog(#"%#",str);
// Assuming...
NSDictionary *dictionary1 = [NSDictionary dictionaryWithObject:[NSArray arrayWithObjects:#"iPhone", #"iPodTouch", nil] forKey:#"ItemList"];
NSDictionary *dictionary2 = [NSDictionary dictionaryWithObject:[NSArray arrayWithObjects:#"iPad", #"iPad2", #"Apple TV", nil] forKey:#"ItemList"];
NSDictionary *dictionary3 = [NSDictionary dictionaryWithObject:[NSArray arrayWithObjects:#"iMac", #"MacBook Pro", #"Mac Pro", nil] forKey:#"ItemList"];
NSArray *arrItems = [NSArray arrayWithObjects:dictionary1, dictionary2, dictionary3, nil];
// create string list
NSString *strItemList = [[arrItems valueForKeyPath:#"#unionOfArrays.ItemList"] componentsJoinedByString:#", "];
NSLog(#"All Items List: %#", strItemList);
Output:
All Items List: iPhone, iPodTouch, iPad, iPad2, Apple TV, iMac, MacBook Pro, Mac Pro
This method will return you the nsmutablestring with comma separated values from an array
-(NSMutableString *)strMutableFromArray:(NSMutableArray *)arr withSeperater:(NSString *)saperator
{
NSMutableString *strResult = [NSMutableString string];
for (int j=0; j<[arr count]; j++)
{
NSString *strBar = [arr objectAtIndex:j];
[strResult appendString:[NSString stringWithFormat:#"%#",strBar]];
if (j != [arr count]-1)
{
[strResult appendString:[NSString stringWithFormat:#"%#",seperator]];
}
}
return strResult;
}
when i convert my array by following method , it adds () charracter.
i want to remove the () how can i do it..
NSMutableArray *rowsToBeDeleted = [[NSMutableArray alloc] init];
NSString *postString =
[NSString stringWithFormat:#"%#",
rowsToBeDeleted];
int index = 0;
for (NSNumber *rowSelected in selectedArray)
{
if ([rowSelected boolValue])
{
profileName = [appDelegate.archivedItemsList objectAtIndex:index];
NSString *res = [NSString stringWithFormat:#"%d",profileName.userID];
[rowsToBeDeleted addObject:res];
}
index++;
}
UPDATE - 1
when i print my array it shows like this
(
70,
71,
72
)
Here's a brief example of deleting the given characters from a string.
NSString *someString = #"(whatever)";
NSCharacterSet *charSet = [NSCharacterSet characterSetWithCharactersInString:#"()"];
NSMutableString *mutableCopy = [NSMutableString stringWithString:someString];
NSRange range;
for (range = [mutableCopy rangeOfCharacterFromSet:charSet];
range.location != NSNotFound;
[mutableCopy deleteCharactersInRange:range],
range = [mutableCopy rangeOfCharacterFromSet:charSet]);
All this does is get a mutable copy of the string, set up a character set with any and all characters to be stripped from the string, and find and remove each instance of those characters from the mutable copy. This might not be the cleanest way to do it (I don't know what the cleanest is) - obviously, you have the option of doing it Ziminji's way as well. Also, I abused a for loop for the hell of it. Anyway, that deletes some characters from a string and is pretty simple.
Try using NSArray’s componentsJoinedByString method to convert your array to a string:
[rowsToBeDeleted componentsJoinedByString:#", "];
The reason you are getting the parenthesis is because you are calling the toString method on the NSArray class. Therefore, it sounds like you just want to substring the resulting string. To do this, you can use a function like the following:
+ (NSString *) extractString: (NSString *)string prefix: (NSString *)prefix suffix: (NSString *)suffix {
int strLength = [string length];
int begIndex = [prefix length];
int endIndex = strLength - (begIndex + [suffix length]);
if (endIndex > 0) {
string = [string substringWithRange: NSMakeRange(begIndex, endIndex)];
}
return string;
}
Trying to manipulate the contents of a txtField in the textFieldDidEndEditing. What we want to do is rotate the entire contents left and then append the current character at the end.
This is to allow a user to enter a money value without a decimal point.
This is what we have so far but I'm not sure this is the best way to approach this. Nor is this code working as expected.
Any help appreciated.
//easier input for total
if (textField == txtGrandTotal)
{
//copy contents of total to string2
NSString *string1 = txtGrandTotal.text;
NSMutableString *string2;
//now string2 contains the buffer to manipulate
string2 = [NSMutableString stringWithString: string1];
//so, copy it to strMoney2
strMoney2 = string2;
int charIndex;
//for all character in strMoney2, move them rotated left to strMoney1
for (charIndex = 0; charIndex < [strMoney2 length]; charIndex++)
{
NSString *strChar = [strMoney2 substringWithRange: NSMakeRange(charIndex, 1)];
[strMoney1 insertString:strChar atIndex:charIndex+1];
}
//now append the current character to strMoney1
NSString *strCurrentChar = [string1 substringWithRange: NSMakeRange([string1 length], 1)];
[strMoney1 appendString:strCurrentChar];
//move manipulated string back to txtGrandTotal
txtGrandTotal.text = strMoney1;
}
Out of a zillion ways to approach this, this is quite short:
NSString *res = [NSString stringWithFormat:#"%#%#",
[input substringFromIndex:1],
[input substringToIndex:1]
];
or shorter:
NSString *res = [[input substringFromIndex:1]
stringByAppendingString:[input substringToIndex:1]];
i have to create an 2images and 3 labels by using code (cgrectmake)and i am having X location, y location, width and height all are stored in arrays(which i have retrieved from the web services)how can i create the image and labels can any one help me
You can join the elements of an array together with the NSString componentsJoinedByString class method:
NSString myString = [myNSArray componentsJoinedByString:#"x"];
where x is the characters you'd like to appear between each array element.
Edited to add
So in your newly-added code if these are the label values:
lbl = #"zero"
lbl1 = #"one"
lbl2 = #"two"
and you want to join them together with a space character then if you did this:
NSString *temp = [labelArray componentsJoinedByString:#" "];
NSLog(#"temp = %#", temp);
then this is what would be logged:
zero one two
Edited to further add
If you are instead trying to join the label values together to make xml elements then you might do something like this:
NSString *joinedElements = [labelArray componentsJoinedByString:#"</label><label>"];
NSString *temp = [NSString stringWithFormat:#"<label>%#</label>", joinedElements];
NSLog(#"temp = %#", temp);
then this is what would be logged:
<label>zero</label><label>one</label><label>two</label>
may be this is usefull to you.
NSString *str;
str = [arrayName objectAtIndex:i(Index NO)];
OK by this easily you can access object from the array. any type of object u can fetch this way only reception object type are change in left side.
Best of Luck.
Most objects have a -description method which returns a string representation of the object:
- (NSString *)description;
For example:
NSArray *array = [NSArray arrayWithObjects:#"The", #"quick", #"brown", #"fox", nil];
NSLog(#"%#", array); // prints the contents of the array out to the console.
NSString *arrayDescription = [array description]; // a string
It would help to know what you want to do with the string (how will you use the string). Also, what kind of objects do you have in the array?
In that case, Matthew's answer is one possibility. Another might be to use an NSMutableString and append the individual items, if you need control over how the string is created:
NSMutableString *string = [NSMutableString string];
if ([array count] >= 3) {
[string appendString:[array objectAtIndex:0]];
[string appendFormat:#"blah some filler text %#", [array objectAtIndex:1]];
[string appendString:[array objectAtIndex:2]];
}
I'm trying to include the elements of an array in the NSString that's returned by the -description method in my class. No clue how to do this in Objective-C...in Java there's string concatenation or StringBuilder, what's the equivalent in Obj-C?
TIA..
Just use NSArray's componentsJoinedByString: method with whatever you want between them as the argument.
NSString *elementsSquishedTogether = [myArray componentsJoinedByString:#""];
NSString *connectedByACommaAndSpace = [myArray componentsJoinedByString:#", "];
If you have a C array, you can turn it into an NSArray with NSArray *converted = [NSArray arrayWithObjects:yourCArray count:yourArrayCount].
The title of your thread talks about C arrays, so here's a modification of jsumners' answer that will deal wiith C arrays.
myArray is assumed to be an ivar declared thusly:
int* myArray;
storage for myArray is assumed to be malloc'd at some point and the size of it is in an ivar declared:
int myArraySize;
The code for description goes something like
- (NSString *)description
{
NSMutableString *returnString = [[[NSMutableString alloc] init] autorelease];
for (int i = 0 ; i < myArraySize ; i++)
{
if (i > 0)
{
[returnString appendString: #", "];
}
[returnString appendFormat: #"%d", myArray[i]];
}
return [NSString stringWithFormat: #"[%#]", returnString];
}
There are variations. The above version formats the string with bracket delimiters and commas between elements. Also, it returns an NSString instead of an NSMutableString which is not a big deal, but I feel that if you say you are returning an immutable object, you probably should.
The following could should "build" a string representation of your array. Notice that it is using the -description method of the objects in the array. If you want something different you will have to make the necessary change.
- (NSString *)description: (id) myArr {
NSMutableString *returnString = [[[NSMutableString alloc] init] autorelease];
for (int i = 0, j = [myaArr count]; i < j; i++) {
[returnString appendString: [[myArr objectAtIndex: i] description]];
}
return [NSString stringWithString: returnString];
}
Edit:
As JeremyP said, I answered this using Objective-C arrays. I guess I just forgot the question when I started writing my code. I'm going to leave my answer as an alternative way to do it, though. I've also fixed the return string type from a mutable string to an immutable string (as it should be).