CODEWITHSUNDEEP
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John Smith
John Smith

Reputation: 630

Show each object from NSMutableDictionary in log

Here's a bit of a newbie question.

I have a NSMutableDictionary *dict

which in the log looks like this:

"test1" = "5";
"test2" = "78";
"test3" = "343";
"test4" = "3";

I need to print each number by itself, but I'm pretty poor at arrays and FOR-sentences.

I was thinking something like:

    for (dict) {
    double number = [[[dict allKeys] objectAtIndex:0] doubleValue];

    NSLog(@"Number: %f",number); 

}

Which I want to look like this in the log on each line:

Number: 5
Number: 78
Number: 343
Number: 3

But obviously my "FOR"-method is gibberish.

Any help would be appreciated.

Upvotes: 1

Views: 1515

Answers (5)

Luiz Carlos Querino Filho
Luiz Carlos Querino Filho

Reputation: 765

You use a fast enumeration for to do this. It iterates over all the keys in the dictionary:

for (NSString *key in dict) {
    double number = [[dict objectForKey:key] doubleValue];
    NSLog(@"Number: %f", number);
}

Upvotes: 3

Mat
Mat

Reputation: 7633

As already mentioned fast-enumeration is preferable in these cases, but you could also do something like this:

for (int i =0; i<[dict count]; i++){
        NSString *str=[dict objectForKey:[NSString stringWithFormat:@"test%d",i+1]];
        NSLog(@"%@",str);
}

Upvotes: 0

zaph
zaph

Reputation: 112855

Using blocks:

NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                            @"5",   @"test1",
                            @"78",  @"test2",
                            @"343", @"test3",
                            @"3",   @"test4",
                            nil];

[dictionary enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
    NSLog(@"Number: %@", obj);
}];

NSLog output:

Number: 5
Number: 3
Number: 343
Number: 78

Upvotes: 3

runmad
runmad

Reputation: 14886

The first answer has two objects being created with the name "number". Instead do:

for (NSString *key in dict) {
    NSLog(@"Number as double: %f", [[dict objectForKey:key] doubleValue]);
    NSLog(@"Number as string: %@", [dict objectForKey:key]);
}

What's great about fast enumeration is that it creates the object for you (and auto-release them). The key is what's being given to you when fast-enumerating through NSDictionaries. Because you now have the key, you just grab the objectAtKey. In your case, it's a string in your dictionary, so you'll have to either convert it to a double (or whatever type you need), or output as a string. I added examples for both cases above. Good luck!

Upvotes: 0

tilo
tilo

Reputation: 14169

If you just want to log these numbers, try the following: 

for (NSString *number in dict) {
    NSLog(@"Number: %@",[dict objectForKey:number]);
}

Upvotes: 0

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