这两个函数只会在类加载的时候掉用一次 之后不会在调用 也不用调用［super xxx］

/// 0 执行1次而已 + (void)load {    NSLog(@" 0:%s", __func__);}/// 1 执行1次而已+ (void)initialize {    NSLog(@" 1:%s", __func__);}复制代码

常规的对象函数

/// 2- (instancetype)init {    self = [super init];    if (self) {        NSLog(@" 2:%s", __func__);    }    return self;}/// 3- (void)loadView {    [super loadView];    NSLog(@" 3:%s", __func__);}/// 4- (void)viewDidLoad {    [super viewDidLoad];    NSLog(@" 4:%s", __func__);}/// 5- (void)viewWillAppear:(BOOL)animated {    [super viewWillAppear:animated];    NSLog(@" 5:%s", __func__);}/// 6- (void)updateViewConstraints {    [super updateViewConstraints];    NSLog(@" 6:%s", __func__);}/// 7- (void)viewWillLayoutSubviews {    [super viewWillLayoutSubviews];    NSLog(@" 7:%s", __func__);}/// 8- (void)viewDidLayoutSubviews {    [super viewDidLayoutSubviews];    NSLog(@" 8:%s", __func__);}/// 9- (void)viewDidAppear:(BOOL)animated {    [super viewDidAppear:animated];    NSLog(@" 9:%s", __func__);}/// 10- (void)viewWillDisappear:(BOOL)animated {    [super viewWillDisappear:animated];    NSLog(@"10:%s", __func__);}/// 11- (void)viewDidDisappear:(BOOL)animated {    [super viewDidDisappear:animated];    NSLog(@"11:%s", __func__);}复制代码