1/* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#import "NSArray+Extensions.h" 18 19@implementation NSArray (WALTExtensions) 20- (NSNumber *)medianValue { 21 NSArray<NSNumber *> *sorted = [self sortedArrayUsingSelector:@selector(compare:)]; 22 const NSUInteger count = sorted.count; 23 if (count == 0) { 24 return nil; 25 } 26 27 if (count % 2) { 28 return [sorted objectAtIndex:count / 2]; 29 } else { 30 return [NSNumber numberWithDouble:0.5 * ([sorted objectAtIndex:count / 2].doubleValue + 31 [sorted objectAtIndex:count / 2 - 1].doubleValue)]; 32 } 33} 34@end 35