數(shù)組

[array[i] isEqual:array2[i]]
判斷兩個(gè)數(shù)組元素是否相等

[array[i] == array2[i]]
判斷兩個(gè)元素地址是否相等

[array componentsJoinedByString:@"."]
將所有元素之間加入.連接成字符串

enumerateObjectsUsingBlock快速遍歷

sortedArrayUsingComparator排列

reverseObjectEnumerator.allObjects將數(shù)組倒過來(排序)

Masonry

更新的約束要在指定的方法中

// this is Apple's recommended place for adding/updating constraints
- (void)updateConstraints {

    [self.growingButton updateConstraints:^(MASConstraintMaker *make) {
        make.center.equalTo(self);
        make.width.equalTo(@(self.buttonSize.width)).priorityLow();
        make.height.equalTo(@(self.buttonSize.height)).priorityLow();
        make.width.lessThanOrEqualTo(self);
        make.height.lessThanOrEqualTo(self);
    }];
    
    //according to apple super should be called at end of method
    [super updateConstraints];
}