第一题

setInterval每次执行的时候，都会把setInterval cb加入宏任务队列，每次事件环循环，在js执行栈的时候setInterval执行，将
setInterval cb放入宏任务队列
clearInterval(interval);清除宏任务队列里面的setInterval cb回调函数，并停止setInterval运行，每次事件环循环就不会setInterval执行了，就不会有新的setInterval cb放入宏任务队列了

console.log('start');
// setInterval1
const interval = setInterval(() => {
    console.log('setInterval');
}, 0)
// setTimeout1
setTimeout(() => {
    console.log('setTimeout 1')
    Promise.resolve()
        // promsie3
        .then(() => {
            console.log('promise 3')
        })
        // promise4
        .then(() => {
            console.log('promise 4')
        })
        // promise5
        .then(() => {
            // setTimeout2
            setTimeout(() => {
                console.log('setTimeout 2');
                Promise.resolve()
                    // promise6
                    .then(() => {
                        console.log('promise 5');
                    })
                    // promise7
                    .then(() => {
                        console.log('promise 6');
                    })
                    // promise8
                    .then(() => {
                        clearInterval(interval);
                    })
            })
        })
})
Promise.resolve()
    // promise1
    .then(() => {
        console.log('promise 1');
    })
    // promise2
    .then(() => {
        console.log('promise 2');
    })

第二道题

time 12m

// setTimeout1
setTimeout(() => {
    console.log('setTimeout 1');
    // setTimeout3
    setTimeout(() => {
        console.log('setTimeout 3');
    }, 1000);
    Promise.resolve()
    // promise4
        .then(data => {
        console.log('then3');
    });
},0)
Promise.resolve()
// promise1
    .then(data => {
    console.log('then1');
    console.log('then2');
    Promise.resolve()
    // promise3
        .then(data1 => { console.log('then6') });
});
Promise.resolve()
// promise2
    .then(data => {
    console.log('then4');
    console.log('then5');
    // setTimeout2
    setTimeout(() => {
        console.log('setTimeout 2');
    }, 1000);
})
console.log(2);

在js执行栈运行的promise，会把promise cb放入微任务队列中，js执行栈中promise1 cb与promise2 cb今日微任务栈，微任务执行时，从前到后运行，promise1 cb把promise3 cb放入js微任务栈
promise1 cb运行打印then1、then2，放入promise3-1 cb，promise3-1 cb，promise3-3 cb，之后promise2运行、
多个Promise.resolve() then cb是同时加进去的，同步代码

// setTimeout1
/*setTimeout(() => {
    console.log('setTimeout 1');
    // setTimeout3
    setTimeout(() => {
        console.log('setTimeout 3');
    }, 1000);
    Promise.resolve()
        // promise4
        .then(data => {
            console.log('then3');
        });
}, 0)*/
Promise.resolve()
    // promise1
    .then(data => {
        console.log('then1');
        console.log('then2');
        Promise.resolve()
            // promise3-1
            .then(data1 => {
                console.log('then6')
            });
        Promise.resolve()
            // promise3-2
            .then(data1 => {
                console.log('then6-2')
            });
        Promise.resolve()
            // promise3-3
            .then(data1 => {
                console.log('then6-3')
            });
    });
Promise.resolve()
    // promise2
    .then(data => {
        console.log('then4');
        console.log('then5');
        // setTimeout2
        /*        setTimeout(() => {
                    console.log('setTimeout 2');
                }, 1000);*/
    })
    .then(data => {
        console.log('then4-2');
        console.log('then5-2');
        // setTimeout2
        /*    setTimeout(() => {
                console.log('setTimeout 2');
            }, 1000);*/
    })
    .then(data => {
        console.log('then4-3');
        console.log('then5-3');
    })
console.log(2);

then链式调用需要上一个then cb运行完成后才会加进微任务队列，下一个then cb加进去时，可能不会立即运行，因为它上面可能有别的微任务，当两个then回调时，是分别进行的，它们的结果会交叉显示

Promise.resolve()
    // promise1
    .then(data => {
        console.log('then1');
        console.log('then2');
        Promise.resolve()
            // promise3
            .then(data1 => {
                console.log('then6')
            })
            .then(data => {
                console.log('then6-1')
            })
            .then(data => {
                console.log('then6-2')
            })
        /*  Promise.resolve()
              // promise3
              .then(data1 => {
                  console.log('then6-2')
              });
          Promise.resolve()
              // promise3
              .then(data1 => {
                  console.log('then6-3')
              });*/
    });
Promise.resolve()
    // promise2
    .then(data => {
        console.log('then4');
        console.log('then5');
    })
    .then(data => {
        console.log('then4-2');
        console.log('then5-2');
    })
    .then(data => {
        console.log('then4-3');
        console.log('then5-3');
    })
console.log(2);

// setTimeout1
setTimeout(() => {
    console.log('setTimeout 1');
    // setTimeout3
    setTimeout(() => {
        console.log('setTimeout 3');
    }, 1000);
    Promise.resolve()
        // promise4
        .then(data => {
            console.log('then3');
        });
}, 0)
Promise.resolve()
    // promise1
    .then(data => {
        console.log('then1');
        console.log('then2');
        Promise.resolve()
            // promise3
            .then(data1 => {
                console.log('then6')
            });
        Promise.resolve()
            // promise3
            .then(data1 => {
                console.log('then6-2')
            });
    });
Promise.resolve()
    // promise2
    .then(data => {
        console.log('then4');
        console.log('then5');
        // setTimeout2
        setTimeout(() => {
            console.log('setTimeout 2');
        }, 1000);
    })
    .then(data => {
        console.log('then4-2');
        console.log('then5-2');
        // setTimeout2
        setTimeout(() => {
            console.log('setTimeout 2');
        }, 1000);
    })
console.log(2);

题目4

time 20m16s

题目5

time 23m06s