Question

我希望在数组中的每个对象之间休眠或等待php之类的随机时间

sleep(rand(10,300));

然后console.log

var array1 = ['msg1', 'msg2', 'msg3'];

像这样

msg1 然后等待20秒
msg2 然后等待30秒
msg3 然后等待50秒

我没有尝试超时，但是问题是每50秒发送3个对象我要在数组随机时间内foreach对象

mycode

var array1 = ['msg1', 'msg2', 'msg3'];
array1.forEach(function(element) {
    setTimeout(function(){
        console.log(element);
    }, 5000);
});

Answer 1

您的代码将立即调用所有setTimeout。相反，您可以将这些呼叫链接起来，如下所示：

var array1 = ['msg1', 'msg2', 'msg3'];
console.log("Wait for it...");

(function loop(arr) {
     if (!arr.length) return; // all done!
     setTimeout(() => {
         console.log(arr[0]);
         // Only after having output this array value, proceed with the next timeout:
         loop(arr.slice(1));
     }, 500 + Math.floor(Math.random() * 5000)); // Provide some randomness
})(array1); // Immediately invoked function expression (IIFE)

Answer 2

下面是一个随机setTimeout的示例：

const arr = ['msg1', 'msg2', 'msg3'];

function loop(arr) {

  // Deconstruct the array into the first
  // element, and the rest
  const [head, ...tail] = arr;

  // if the array isn't empty
  if (head) {

    // Grab a random time between 1 and 10 seconds
    const time = Math.floor(Math.random() * (10 - 1) + 1) * 1000;
    console.log(head, time);

    // Call the function again with the remaining
    // array (tail), after `time`
    setTimeout(() => loop(tail), time);
  }
}

// Call `loop` with a copy of the array
loop([...arr]);

Answer 3

如果您的环境支持async/await，则可以：

const time = 50 // base seconds
const randomTime = () => Math.floor(Math.random() * time * 1000) // miliseconds
const messages = ['msg1', 'msg2', 'msg3']

function delayedMessage(msg, miliseconds) {
  return new Promise(resolve => {
    setTimeout(() => {
      console.log(msg, miliseconds)
      resolve()
    }, miliseconds)
  })
}

async function logMessages(msgArr) {
  for (const index in msgArr) {
    await delayedMessage(messages[index], randomTime())
  }
}

logMessages(messages)

在节点js数组中的每个对象之间休眠

3 个答案: