javascript - 有 promise 和取款的麻烦

昨天，我开始学习React并在Promises方面遇到一些麻烦。

var p1 = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve(3)
  }, 2000);
})

p1
  .then(() => {
    setTimeout(() => {
      // First block
      console.log("This was executed.")
    }, 1000)
  })
  .then(() => {
      // Second block
    console.log("This block is executed too.");
  })

使用以下代码，我如何首先执行第一个块，然后执行第二个块？

最佳答案

您还需要在第一个then块中返回Promise

var p1 = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve(3)
  }, 2000);
})

p1
  .then(() => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
          // First block
          console.log("This was executed.")
          resolve();
        }, 1000)
    }
  })
  .then(() => {
      // Second block
    console.log("This block is executed too.");
  })

关于javascript - 有 promise 和取款的麻烦，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/57430787/