我有這樣一個(gè)數(shù)組：NSArray *arr = @[@{@"index" : @"3", @"key" : @"value"},
@{@"index" : @"4", @"key" : @"value"},
@{@"index" : @"1", @"key" : @"value"},
@{@"index" : @"2", @"key" : @"value"}];要重新按照字典里的index值排序變成這樣：NSArray *arr = @[@{@"index" : @"1", @"key" : @"value"},
@{@"index" : @"2", @"key" : @"value"},
@{@"index" : @"3", @"key" : @"value"},
@{@"index" : @"4", @"key" : @"value"}];
2 回答
30秒到達(dá)戰(zhàn)場
TA貢獻(xiàn)1828條經(jīng)驗(yàn) 獲得超6個(gè)贊
NSArray *array = [NSArray array];
[array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2){
NSNumber index1 = [obj1 valueForKey:@"index"];
NSNumber index2 = [obj2 valueForKey:@"index"]; return [index1 compare:index2];
}];就是這樣了。
慕尼黑5688855
TA貢獻(xiàn)1848條經(jīng)驗(yàn) 獲得超2個(gè)贊
Compare method
Either you implement a compare-method for your object:
- (NSComparisonResult)compare:(Person *)otherObject {
return [self.birthDate compare:otherObject.birthDate];}
NSArray *sortedArray;
sortedArray = [drinkDetails sortedArrayUsingSelector:@selector(compare:)];NSSortDescriptor (better)
or usually even better: (The default sorting selector of NSSortDescriptor is compare:)
NSSortDescriptor *sortDescriptor; sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:@"birthDate" ascending:YES] autorelease];NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];NSArray *sortedArray; sortedArray = [drinkDetails sortedArrayUsingDescriptors:sortDescriptors];
Blocks (shiny!)
There's also the possibility of sorting with a block since 10.6:
NSArray *sortedArray;
sortedArray = [drinkDetails sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
NSDate *first = [(Person*)a birthDate];
NSDate *second = [(Person*)b birthDate]; return [first compare:second];
}];- 2 回答
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