Convert a string like "ff0000" to hexadecimal number in objective c

Question

I need to convert a string input from UI to a hexadecimal number in objective c. The string is an HTML color code like "ff0000" (the '#' will be dealt with diagrammatically) and it is supposed to be converted to the number ff0000 in order to provide color selection. Alternatively, is there a color chooser in objective c? didn't find one in the xib objects.

Answer 1

From Objective C parse hex string to integer

unsigned result = 0;
NSScanner *scanner = [NSScanner scannerWithString:@"ff0000"];
[scanner scanHexInt:&result];

or using "c":

uint32_t value;
NSString *stringValue = @"ff0000";
const char *string = [stringValue cStringUsingEncoding:NSUTF8StringEncoding];
sscanf(string, "%x" , &value);

Answer 2

You can use the below line for conversion. Its just one line code:

NSString *hexString = @"01FFFFAB";
length = (UInt64)strtoull([sizeLine UTF8String], NULL, 16);
NSLog(@"The required Length is %d", length);

Happy Coding!!!