I am trying to build a small table using NSString. I cannot seem to format the strings properly.
Here is what I have
[NSString stringWithFormat:@"%8@: %.6f",e,v]
where e is an NSString from somewhere else, and v is a float.
What I want is output something like this:
Grapes: 20.3
Pomegranates: 2.5
Oranges: 15.1
What I get is
Grapes:20.3
Pomegranates:2.5
Oranges:15.1
How can I fix my format to do something like this?
you could try using - stringByPaddingToLength:withString:startingAtIndex:
NSDictionary* fruits = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithFloat:20.3], @"Grapes",
[NSNumber numberWithFloat:2.5], @"Pomegranates",
[NSNumber numberWithFloat:15.1], @"Oranges",
nil];
NSUInteger longestNameLength = 0;
for (NSString* key in [fruits allKeys])
{
NSUInteger keyLength = [key length];
if (keyLength > longestNameLength)
{
longestNameLength = keyLength;
}
}
for (NSString* key in [fruits allKeys])
{
NSUInteger keyLength = [key length];
NSNumber* object = [fruits objectForKey:key];
NSUInteger padding = longestNameLength - keyLength + 1;
NSLog(@"%@", [NSString stringWithFormat:@"%@:%*s%5.2f", key, padding, " ", [object floatValue]]);
}
Output:
Oranges: 15.10 Pomegranates: 2.50 Grapes: 20.30
The NSNumberFormatter class is the way to go!
Example:
NSNumberFormatter *numFormatter = [[NSNumberFormatter alloc] init];
[numFormatter setPaddingCharacter:@"0"];
[numFormatter setFormatWidth:2];
NSString *paddedString = [numFormatter stringFromNumber:[NSNumber numberWithInteger:integer]];
[numFormatter release];
I think you want something like
[NSString stringWithFormat:@"%-9@ %6.1f",[e stringByAppendingString:@":"],v]
since you want padding in front of the float to make it fit the column, though if the NSString is longer than 8, it will break the columns.
%-8f left-aligns the string in a 9-character-wide column (9-wide since the : is appended to the string beforehand, which is done so the : is at the end of the string, not after padding spaces); %6.1f right-aligns the float in a 6-char field with 1 decimal place.
edit: also, if you're viewing the output as if it were HTML (through some sort of web view, for instance), that may be reducing any instances of more than one space to a single space.
