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切换case,如果case A或B,我想做一些事情,如果case A或B,我想做其他事情?

javascript

-1

user1283776 · 技术社区 · 7 年前

看看这个switch case语句。案例“回应”和“错误”有很多共同点,但也有一条线将它们区分开来。

            switch (data.type) {
                case 'response':
                    const transactionId = data.trans_id;
                    const callbacks = commandCallbacks[transactionId];

                    if (!callbacks) {
                        if (logger) logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
                        break;
                    }

                    clearTimeout(callbacks.timedOutTimer);
                    callbacks.resolver(data);
                    break;
                case 'error':                
                    const transactionId = data.trans_id;
                    const callbacks = commandCallbacks[transactionId];

                    if (!callbacks) {
                        if (logger) logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
                        break;
                    }

                    clearTimeout(callbacks.timedOutTimer);
                    callbacks.rejecter(data);
                    break;
                case 'information':
                case 'progress':
                default:
                    break;
            }

6 回复 | 直到 7 年前

Buczkowski 7 年前

        switch (data.type) {
            case 'error':
            case 'response':
                const transactionId = data.trans_id;
                const callbacks = commandCallbacks[transactionId];

                if (!callbacks) {
                    if (logger) logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
                    break;
                }

                clearTimeout(callbacks.timedOutTimer);
                 data.type === 'response' ? callbacks.resolver(data) : callbacks.rejecter(data);
                break;
            case 'information':
            case 'progress':
            default:
                break;
        }

此外,如果您有更多的选项来签入交换机,您可以将其更改为 if .

CertainPerformance 7 年前

使用括号表示法和条件运算符访问 callbacks ,然后调用函数:

switch (data.type) {
  case 'response':
  case 'error':
    const transactionId = data.trans_id;
    const callbacks = commandCallbacks[transactionId];

    if (!callbacks) {
      if (logger) logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
      break;
    }

    clearTimeout(callbacks.timedOutTimer);
    const fn = callbacks[data.type === 'response' ? 'resolver' : 'rejecter'];
    fn(data);
    break;
    // ...

注意,如果函数依赖于 this 回调 ,使用 .call 取而代之的是:

fn.call(callbacks, data);

这实际上与OR和XOR没有任何关系-不同 case

Nick Parsons Felix Kling 7 年前

让 response error 通过移动你的 case

switch (data.type) {
  case 'response':
  case 'error':
    const transactionId = data.trans_id;
    const callbacks = commandCallbacks[transactionId];

    if (!callbacks) {
      if (logger) logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
      break;
    }

    clearTimeout(callbacks.timedOutTimer);
    if(data.type === 'response') {
      callbacks.resolver(data);
    } else if(data.type === 'error' {
      callbacks.rejecter(data);
    }
    break;

  case 'information':
  case 'progress':
}

Nina Scholz 7 年前

您可以使用一个函数来获取回调,然后使用具有正确目标值的对象调用它。

function getCallbacks({ trans_id }) {
    const callbacks = commandCallbacks[trans_id];
    if (!callbacks) {
        if (logger) logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
        return;
    }
    return callbacks;
}

switch (data.type) {
    case 'response':
    case 'error':
        let cb = getCallbacks(data);
        if (!cb) break;
        clearTimeout(cb.timedOutTimer);
        cb[{ response: 'resolver', error: 'rejecter' }[data.type]](data);
}

einarmagnus 7 年前

我会完全跳过switch语句,这样写:

if (["reponse", "error"].includes(data.type)) {
    const transactionId = data.trans_id;
    const callbacks = commandCallbacks[transactionId];
    if (callbacks) {
        const callback = {
            response: data => callbacks.resolver(data),
            error: data => callbacks.rejecter(data)
        }[data.type];
        clearTimeout(callbacks.timedOutTimer);
        callback(data);
    } else if (logger) {
        logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
    }
}

user1283776 7 年前

这是我最好的尝试:

            switch (data.type) {
                case 'response':
                case 'error':
                    const transactionId = data.trans_id;
                    const callbacks = commandCallbacks[transactionId];

                    if (!callbacks) {
                        if (logger) logger(`Dropping received message that was not requested, transactionId: ${transactionId}`);
                        break;

                    }
                    clearTimeout(callbacks.timedOutTimer);

                    switch (data.type) {
                        case 'response':
                            callbacks.resolver(data);
                        case 'error':
                            callbacks.rejecter(data);
                    }

                    break;
                case 'information':
                case 'progress':
                default:
                    break;
            }