如何将 NSArray 的 objectAtIndex:i 添加到 NSMutableDictionary答案

【问题标题】：How to Add objectAtIndex:i of NSArray to NSMutableDictionary如何将 NSArray 的 objectAtIndex:i 添加到 NSMutableDictionary
【发布时间】：2017-03-07 13:19:03
【问题描述】：

如何将objectAtIndex:i 的NSArray 添加到NSMutableDictionary

我试过了

for(int i=0 ;i<=[user count]; i++){

NSMutableDictionary * dict = [NSMutableDictionary :[user objectAtIndex:i]];

}

【问题讨论】：

您可以使用 NSMutableDictionary *Dic = [[NSMutableDictionary alloc] initWithObjectsAndKeys:[Arr objectAtIndex:i],@"somekey", nil] 之类的键设置值

标签： ios objective-c nsarray nsmutabledictionary

【解决方案1】：

使用枚举块代替 for 循环：

    NSArray *arr;
    NSMutableDictionary *dic = [[NSMutableDictionary alloc]init];
    [arr enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {

        [dic setObject:obj forKey:[NSString stringWithFormat:@"%lu", (unsigned long)idx]];
    }];

【讨论】：

【解决方案2】：

 NSMutableDictionary *dic = [[NSMutableDictionary alloc] initWithCapacity:[user count]];

 for(int i=0 ;i<[user count]; i++) {
    [dic setObject:[user objectAtIndex:i] forKey:[NSString stringWithFormat:@"%i", i]];
 }

小心这个：i

【讨论】：

【解决方案3】：

试试这个....

NSArray * myArray = [NSArray arrayWithObjects:@"a", @"b", @"c"];

NSDictionary * dict = [NSDictionary dictionaryWithObject:myArray forKey:@"threeLetters"];

NSMutableDictionary * mutableDict = [NSMutableDictionary dictionaryWithCapacity:10];
[mutableDict setObject:myArray forKey:@"threeLetters"];

【讨论】：