Print a line 10 times in Objective-C? - objective-c

Question

I know that print line is NSLog. How do I print a line 10 times in Objective-C?

Answer 1

I haven't had a chance to refactor yet, but something like this should work!
for(int i = 0; i < 10; i++)
{
if(i == 0)
NSLog(#"A line");
else if (i == 1)
NSLog(#"A line");
else if (i == 2)
NSLog(#"A line");
else if (i == 3)
NSLog(#"A line");
else if (i == 4)
NSLog(#"A line");
else if (i == 5)
NSLog(#"A line");
else if (i == 6)
NSLog(#"A line");
else if (i == 7)
NSLog(#"A line");
else if (i == 8)
NSLog(#"A line");
else if (i == 9)
NSLog(#"A line");
}

Answer 2

Another while loop option.
//
// main.m
// Pritner
//
// Created by Joshua Caswell on 7/19/12.
//
#import <Foundation/Foundation.h>
#import <objc/runtime.h>
// A Pritner instance holds and displays a passed-in string. The string is publicly
// unchangeable.
#interface Pritner : NSObject
+ (id)pritnerWithLine: (NSString *)newLine;
- (void)printLine;
#property (readonly, copy, nonatomic) NSString * line;
#end
// Extension to manage "class variable" for counting number of created instances
#interface Pritner ()
+ (NSUInteger)numPritnersCreated;
+ (void)setNumPritnersCreated:(NSUInteger)n;
+ (NSUInteger)maxNumPritners;
#property (readwrite, copy, nonatomic) NSString * line;
- (id)initWithLine: (NSString *)line;
#end
#implementation Pritner
#synthesize line;
+ (id)pritnerWithLine: (NSString *)newLine {
id newInstance = [[self alloc] initWithLine:newLine];
if( newInstance ){
NSUInteger createdSoFar = [self numPritnersCreated];
// Only allow maxNumPritners to ever be created; keeping track of them
// is the client's problem.
if( createdSoFar >= [self maxNumPritners] ){
abort();
}
[self setNumPritnersCreated:createdSoFar + 1];
}
return newInstance;
}
// Fake class variable using associated objects; keep count of created instances
char numPritnerKey;
+ (NSUInteger)numPritnersCreated {
NSNumber * n = objc_getAssociatedObject(self, &numPritnerKey);
if( !n ){
n = [NSNumber numberWithUnsignedInteger:0];
[self setNumPritnersCreated:0];
}
return [n unsignedIntegerValue];
}
+ (void)setNumPritnersCreated:(NSUInteger)n {
objc_setAssociatedObject(self,
&numPritnerKey,
[NSNumber numberWithUnsignedInteger:n],
OBJC_ASSOCIATION_RETAIN);
}
// Maximum number of instances ever allowed to be created
+ (NSUInteger)maxNumPritners {
return 10;
}
- (id)initWithLine: (NSString *)newLine {
self = [super init];
if( !self ) return nil;
line = [newLine copy];
return self;
}
- (void)printLine {
NSLog(#"%#", [self line]);
}
#end
int main(int argc, const char * argv[])
{
#autoreleasepool {
while( YES ){
Pritner * p = [Pritner pritnerWithLine:#"I figure, if you're going to build a time machine out of a car, why not do it with some style?"];
[p printLine];
}
}
return 0;
}
Please don't use this in real life.

Answer 3

Don't forget the "object" in "Objective-C".
NSArray *lines = [#"123456789" componentsSeparatedByCharactersInSet:[NSCharacterSet alphanumericCharacterSet]];
[lines enumerateObjectsUsingBlock:^(id obj, NSUInteger i, BOOL* stop) {
NSLog(#"a line");
}];
If you think Objective-C isn't true enough to its Smalltalk roots, you can do something like the following.
typedef void (^LoopBlock)(NSNumber*);
#interface NSNumber (loop)
-(void)to:(NSNumber*)upTo do:(LoopBlock)block;
-(void)timesRepeat:(LoopBlock)block;
#end
#implementation NSNumber (loop)
static NSString *loopSeparator = #"_";
-(void)to:(NSNumber*)upTo do:(LoopBlock)block {
[ [ [#"" stringByPaddingToLength:[upTo unsignedIntegerValue]-[self unsignedIntegerValue]
withString:loopSeparator
startingAtIndex:0
] componentsSeparatedByString:loopSeparator
] enumerateObjectsUsingBlock:^(id obj, NSUInteger i, BOOL* stop) {
block([NSNumber numberWithUnsignedInteger:i+[self unsignedIntegerValue]]);
}
];
}
-(void)timesRepeat:(LoopBlock)block {
[[NSNumber numberWithUnsignedInteger: 1] to:self do:block];
}
#end
int main() {
#autoreleasepool {
[[NSNumber numberWithInt:10]
timesRepeat:^(NSNumber* i){
NSLog(#"a line");
}];
}
}

Answer 4

Use recursion:
print(10);
void print(int i){
if(i == 0)
return;
NSLog(#"print this line");
print(i - 1);
}

Answer 5

Use Grand Central Dispatch another way:
dispatch_apply(10, dispatch_get_main_queue(), ^(size_t curr_iteration){
NSLog(#"a line");
});

Answer 6

Use a goto statement:
int i = 0;
print:
NSLog(#"print this line");
if (i++ < 10) goto print;

Answer 7

Use a for loop:
for (int i = 0; i < 10; i++) {
NSLog(#"print this line");
}

Answer 8

Use Grand Central Dispatch:
__block int i = 0;
__block dispatch_block_t print_block = ^() {
NSLog(#"print this line");
i += 1;
if (i < 10) dispatch_sync(dispatch_get_main_queue(), print_block);
}
dispatch_sync(dispatch_get_main_queue(), print_block);

Answer 9

Use a while loop:
int i = 0;
while (i < 10) {
NSLog(#"print this line");
i += 1;
}