add async await demo

Author: itstrive

async await/a.txt

@@ -0,0 +1 @@
+name is a

async await/b.txt

@@ -0,0 +1 @@
+name is b ^_^

async await/demo.js

@@ -0,0 +1,22 @@
+const fs = require('fs');
+
+function getFile1() {
+	return new Promise(function(resolve, reject) {
+		resolve(fs.readFileSync('a.txt'));
+	});
+}
+
+function getFile2() {
+	return new Promise(function(resolve, reject) {
+		resolve(fs.readFileSync('b.txt'));
+	});
+}
+
+async function show() {
+	let data1 = await getFile1();
+	let data2 = await getFile2();
+	console.log(data1.toString());
+	console.log(data2.toString());
+}
+
+show();

web-knowledge/前端一点新东西.md

@@ -163,4 +163,30 @@
   >
   > })
 
-  - https://itstrive.github.io/striveCode/html5-api/html5%20%E7%94%B5%E6%B1%A0%E4%BF%A1%E6%81%AF.html 
+  - https://itstrive.github.io/striveCode/html5-api/html5%20%E7%94%B5%E6%B1%A0%E4%BF%A1%E6%81%AF.html 
+
+- visibilitychange  页面可见性
+
+  > 用途: 多标签切换，浏览器最小化，提高用户体验
+
+  ```javascript
+  <video src="1.mp4" autoplay id="video1"></video>
+
+  <script>
+    var oVideo=document.querySelector('#video1');
+
+    $(document).on('visibilitychange',function(){
+      if(document.hidden){
+        //oVideo.pause();
+        $(oVideo).animate({volumn:0},1000,'linear',function(){
+        	oVideo.pause();
+        });
+      }else{
+        oVideo.play();
+        $(oVideo).animate({volumn:1},1000,'linear');
+      }
+    });
+  </script>
+  ```
+
+  ​

web-knowledge/前端技巧搜集.md

@@ -115,8 +115,38 @@
    document.write("<script src=\"http://apps.bdimg.com/libs/vue/1.0.14/vue.js\"><\/script>");
    ```
 
-   ​
+6. open出来的窗口，获取父级window
 
+   ```javascript
+   var win=window.open('','MyName','width=200, height=100, left=300');
+
+   win.document.write('我是新页面');
+   win.focus();
+   win.opener.document.write('我是父级');
+   ```
 
+7. 正则判断一个字符串中必须包含数字
 
+   (?=.*\d)  主要是这句，意思代表必须有数字
+
+   ```javascript
+   var reg=/^(?=.*\d)\w{2,5}$/g;
 
+   console.log(reg.test('h')); //false
+   console.log(reg.test('good')); //false
+   console.log(reg.test('w4ell')); //true
+   reg.lastIndex=0;  //别忘记调整index
+   console.log(reg.test('5well')); //true
+   ```
+
+   那，校验字符串中必须包含数字以及大写字母呢？
+
+   ```javascript
+   var reg=/^(?=.*\d)(?=.*[A-Z])\w{2,5}$/g;
+
+   console.log(reg.test('h')); //false
+   console.log(reg.test('Good5')); //true
+   reg.lastIndex=0;  //别忘记调整index
+   console.log(reg.test('w4ell')); //false
+   console.log(reg.test('5Well')); //true
+   ```