Question

我有一系列名字，想要通过A＆amp; A来计算它们。 B前缀。例如，对于此用户名，我希望我的 NSMutableDictionary * cellNum 返回以每个字母开头的名称计数，例如：“A”：“2”＆amp; “B”： “1”

@interface ...
{
    NSArray *users;
    NSMutableDictionary *cellNum;
}

@implementation ...
{
    users = @[@"Ali",@"Armita",@"Babak"];

    for (int i=0;i<users.count;i++)
    {
        if ( [users[i] hasPrefix:@"A"] )
        {
            cellNum[@"a"] = @([cellNum[@"a"] intValue]+1);
        }
        else
        {
            cellNum[@"b"] = @([cellNum[@"b"] intValue]+1);
        }
    }
}

Answer 1

尝试使用此代码：

NSMutableDictionary *cellNum = [NSMutableDictionary dictionary];

[cellNum setObject:@(0) forKey:@"a"];
[cellNum setObject:@(0) forKey:@"b"];

NSArray* users = @[@"Ali",@"Armita",@"Babak"];

for (int i=0;i<users.count;i++)
{
if ( [users[i] hasPrefix:@"A"] ) {
cellNum[@"a"] = @([cellNum[@"a"] intValue]+1);
}
else {
cellNum[@"b"] = @([cellNum[@"b"] intValue]+1);
}
}

这肯定会给你想要的结果：{a = 2; b = 1; }

更新值或设置新密钥＆amp; Objective-C

1 个答案: