diff --git "a/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/.keep" "b/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/.keep"
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git "a/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L1.txt" "b/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L1.txt"
new file mode 100644
index 0000000000000000000000000000000000000000..55e79a991b08ccbe8ee48a9eb3003e379b0d06b0
--- /dev/null
+++ "b/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L1.txt"
@@ -0,0 +1,80 @@
+const MAX_NUMBER = 10;
+let j = 0;
+let my_obj = {a:1, b:2, c:3};
+let my_obj_iter = [1, 2, 3, 4, 5];
+let myArray = [1, 3, 5, 7];
+
+
+/*
+for (let i=0; i<20; i++){
+  console.log(i);
+}
+*/
+
+/*
+while (j < MAX_NUMBER){
+  console.log(j);
+  j++;
+}
+*/
+
+/*
+do {
+  console.log(j);
+  j++;
+} while (j < MAX_NUMBER)
+*/
+
+for (let e in my_obj) {
+  console.log(e, my_obj[e]);
+}
+
+for (let e of my_obj_iter){
+  console.log(e);
+}
+
+myArray.forEach (function (e) {
+  console.log(e**2);
+})
+
+for(let i=-2; i<20; i++){
+    if (i < 0){
+        console.log("负数不判断", i);
+    }else if(i%2===0){
+        console.log("偶数", i);
+    }else{
+        console.log("奇数", i);
+    }
+}
+
+function foo(e) {
+  switch (e) {
+    case 'a':
+      console.log("arg is a");
+      break;
+    case 'b':
+      console.log("arg is b");
+      break;
+    default:
+      console.log("default arg is c");
+  }
+}
+
+foo('e');
+
+function foo2(){
+    try{
+        throw TypeError('test');
+        //throw {'a':1};
+    }catch (e){
+        if (e instanceof TypeError){
+            console.log("TypeError");
+        }else{
+            console.log('Error', e);
+        }
+    }finally{
+        console.log('Done!');
+    }
+}
+
+foo2();
diff --git "a/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L2.txt" "b/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L2.txt"
new file mode 100644
index 0000000000000000000000000000000000000000..00499ed8dc4d0c927bb843d8a0034688cfddab1e
--- /dev/null
+++ "b/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L2.txt"
@@ -0,0 +1,80 @@
+class Rectangle {
+  constructor(width, height){
+    this.width = width;
+    this.height = height;
+    this.name = "rectangle";
+    this._author = "chaos";
+  }
+  
+  static staticMethod(){
+    console.log("this is static method");
+  }
+  
+  getArea(){
+    return this.width * this.height;
+  }
+  
+  get area(){
+    return this.getArea();
+  }
+  
+  set author(name){
+    this._author = name;
+  }
+}
+
+let square = new Rectangle(2, 2);
+console.log(square.area);
+console.log(square._author);
+Rectangle.staticMethod();
+square.author = 'john';
+console.log(square._author);
+
+class Square extends Rectangle {
+  #new_name
+  constructor(a){
+    super(a, a);
+    this.#new_name = "square";
+  }
+
+  get new_name(){
+    return this.#getnewName();
+  }
+  
+  #getnewName() {
+    return this.#new_name;
+  }
+}
+
+function Rectangle2(height, width){
+    this.name = 'rectangle';
+    this.width = width;
+    this.height = height;
+
+    this.getArea = function (){
+        return this.height * this.width;
+    }
+}
+
+let rec = new Rectangle2(2, 3);
+console.log(rec.getArea());
+
+//call
+function Square2(a){
+    Rectangle.call(this, a, a);
+    this.name = 'square';
+}
+//apply
+function Square3(a){
+    Rectangle.apply(this, [a, a]);
+    this.name = 'square';
+}
+//proto
+function Square4(a){
+    this.height = a;
+    this.width = a;
+    this.name = 'square'
+}
+Square4.prototype = new Rectangle();
+let square4 = new Square4(10);
+console.log(square4.getArea());
\ No newline at end of file
diff --git "a/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L3.txt" "b/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L3.txt"
new file mode 100644
index 0000000000000000000000000000000000000000..b44af4ba498fa95b9992ef43320e848311779288
--- /dev/null
+++ "b/\347\254\254\344\272\214\346\234\237\350\256\255\347\273\203\350\220\245/2\347\217\255/2\347\217\255_chaos/\347\254\254\345\215\201\344\271\235\345\221\250/W19_L3.txt"
@@ -0,0 +1,56 @@
+//callback
+document.addEventListener("click", function(e){console.log(e)})
+
+//Promise
+/*
+A Promise is in one of these states:
+
+pending: initial state, neither fulfilled nor rejected.
+fulfilled: meaning that the operation was completed successfully.
+rejected: meaning that the operation failed.
+*/
+const promise1 = new Promise((resolve, reject) => {
+  setTimeout(() => {
+    resolve('foo');
+  }, 300);
+});
+
+promise1.then((value) => {
+  console.log(value);
+  // expected output: "foo"
+});
+
+console.log(promise1);
+// expected output: [object Promise]
+
+function myAsyncFunction(url) {
+  return new Promise((resolve, reject) => {
+    const xhr = new XMLHttpRequest();
+    xhr.open("GET", url);
+    xhr.onload = () => resolve(xhr.responseText);
+    xhr.onerror = () => reject(xhr.statusText);
+    xhr.send();
+  }).then(result => {console.log("SUCCESS", result)})
+      .catch(error => {console.log("FAILURE", error)})
+}
+
+
+// async/await
+function xhrRequest(url){
+    return new Promise((resolve, reject) => {
+        const xhr = new XMLHttpRequest();
+        xhr.open('GET', url);
+        xhr.onload = function(){resolve(xhr.responseText)};
+        xhr.onerror = () => reject(xhr.status);
+        xhr.send();
+    })
+}
+
+async function requestBaidu(url){
+   try{
+    let result = await xhrRequest(url);
+    console.log("DONE", result);
+  }catch (e) {
+    console.log("ERROR", e);
+  }
+}