設定數組
NSArray *array = @[@(1), @(2), @(3), @(4), @(5)];
1、數組遍歷(enumerateObjectsUsingBlock)
代碼示例
//使用枚舉代碼塊遍歷
[array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop){
NSLog(@"%@",obj);//遍歷數組
//idx == 3時退出循環
if(idx == 3){
*stop = YES;
}
}];
/**輸出
*1,2,3,4,5
*1,2,3
*/
以上代碼中obj代表數組參數,idx爲指定數組參數,*stop用於退出與否判斷
2、數組排序(sortedArrayUsingComparator)
代碼示例
//1、升序
[array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
return [obj1 compare obj2];
}];
NSLog(@"%@",array);
//輸出爲1,2,3,4,5
//2、降序
[array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
return [obj2 compare obj1];
}];
NSLog(@"%@",array);
//輸出爲5,4,3,2,1
//3、亂序
[array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
int seed = arc4random_uniform(2);//隨機生成數字
if(seed){
return[obj1 compare: obj2];
}else{
return[obj2 compare: obj1];
}
}];
NSLog(@"%@",array);
//輸出爲隨機排序