Convert binary to decimal in Objective-C

Question

I have a binary sequence in a string. How to convert it to decimal. Is there a built-in function in Objective-C?

Answer 1

NSString * b = @"1101"; long v = strtol([b UTF8String], NULL, 2); NSLog(@"%ld", v); //logs 13 

The disadvantage of this is that it only creates positive numbers.

Answer 2

I could not find the built-in function. So I wrote a simple C function in accordance with the process that we do for conversation.

 (int) BinToInt(char *temp) { int count, total, i, j, tmp; total = 0; count = strlen(temp); for (i = 0; i <= count; i++) { if (temp[count-i] == '1') { tmp = 1; for (j = 1; j < i; j++) tmp *= 2; total += tmp; } } 

Answer 3

[This code seems to need no explanation]

 (void)convertBinaryToNumeric{ NSString *bin_Input = @"1010"; NSString *reverseInput = [self reverseString:bin_Input]; int dec_Output = 0; int dec_Counter = 0; for (int i=0; i<[reverseInput length]; i++) { dec_Output = [[reverseInput substringWithRange:NSMakeRange(i, 1)] intValue] * [self multipliesByTwo:i]; dec_Output = dec_Counter + dec_Output; dec_Counter = dec_Output; } NSLog(@"Bin:%@ Dec:%d",bin_Input,dec_Output); } (NSString *)reverseString:(NSString *)inputStr{ NSMutableString *revStr = [[NSMutableString alloc]initWithString:@""]; for (int i=[inputStr length]-1; i>=0; i--) { [revStr appendString:[inputStr substringWithRange:NSMakeRange(i, 1)]]; } return revStr; } (int)multipliesByTwo:(int)number{ if(number == 0){ return 1; }else{ int bin_value = 2; int multipleBy=0; for (int i=1; i<=number; i++) { if(multipleBy == 0){ multipleBy = bin_value; }else{ multipleBy = multipleBy *2; } } return multipleBy; } return 0; }