sortedArrayUsingComparator int [英] sortedArrayUsingComparator int

问题描述

我有一个字典数组，它对sortedArrayUsingComparator对其进行排序；

I have an array of a dictionary that it sortedArrayUsingComparator sorts them based on the key;

listPerc = [listItem sortedArrayUsingComparator: ^(id a, id b) {
    NSString *first = [a objectForKey:@"perc"];
    NSString *second = [b objectForKey:@"perc"];
    return [first compare:second];

问题在于此键是一个数字，而顺序例如是:1,10、15、17、2、23等. 它不计算数字的大小. 我该怎么办?

the problem is that this key is a numbers, and order is so for example: 1,10, 15, 17, 2, 23, etc. it does not calculate the magnitude of the number. how can I do?

推荐答案

将它们放入NSNumber对象中，然后进行比较.可以将它们存储为以NSNumbers开头(首选方法)，也可以在比较时进行转换(更慢).

Make them into NSNumber objects and compare those instead. Either store them as NSNumbers to start with (preferred method) or convert them when comparing (slower).

将NSString转换为NSNumber可以通过以下方式完成:

Converting an NSString to an NSNumber can be done with:

NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterDecimalStyle];
NSNumber * myNumber = [f numberFromString:string];
[f release];

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