console.log("普通函数方式"); var arr1 = [1, 2, 3, 4, 5]; arr1.forEach(function(e) { console.log(e); }); console.log("箭头函数方式"); var arr2 = [1, 2, 3, 4, 5]; arr2.forEach((e) => console.log(e));
function taskA() { console.log("Task A"); // throw new Error("taskA掉坑里了"); } function taskB() { console.log("Task B"); throw new Error("taskB掉坑里了"); } function onRejected(error) { console.log("onRejected catch Error: A or B", error); } function finalTask() { console.log("Final Task"); } var promise = Promise.resolve(); promise .then(taskA) // 和task A/B .then(taskB) .catch(onRejected) .then(finalTask); console.log('promise finish'); // promise finish 打印顺序