7.2

2 months ago · e3aa69d5bf
3 changed files with 192 additions and 0 deletions
--- a/src/jsStudy/Math.html
+++ b/src/jsStudy/Math.html
@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <script>
+        console.log(Math.abs(-2));//去绝对值
+         console.log(Math.min(10,11,12,16,48,2));//取最小值
+         console.log(Math.max(10,11,12,16,48,2));//取最大值
+         console.log(Math.floor(10.1));//向下取整
+         console.log(Math.ceil(10.1));//向上取整
+         console.log(Math.random())//取0~1之间的随机数
+         function getRandomNum(min,max){
+            //random*（最大值-最小值）+最小值
+            return Math.floor(Math.random()*(max-min)+min);
+         }
+         
+         var n = getRandomNum(10,20);
+         console.log(n);
+
+         //Date
+         console.log(Date.now());
+         console.log(new Date(Date.now()));
+         console.log(new Date(1751436462638).getDate());//2
+         console.log(new Date(1751436462638).getTime());
+         console.log(new Date(1751436462638).getMonth());//0~11代表一到十二月
+         console.log(new Date(1751436462638).getFullYear());//年
+         console.log(new Date(1751436462638).getHours());//时
+         console.log(new Date(1751436462638).getMilliseconds());//毫秒
+         console.log(new Date(1751436462638).getMinutes());//分
+         console.log(new Date(1751436462638).getSeconds());//秒
+         
+         
+         
+         
+         
+         
+         
+    </script>
+</body>
+</html>
--- a/src/jsStudy/dom获取元素.html
+++ b/src/jsStudy/dom获取元素.html
@ -0,0 +1,77 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+
+<body>
+    <!-- dom节点的类型
+    Document:文档树的顶级节点
+    DocumentType:doctype标签
+    Element：网页的html标签
+    Attribute:元素属性
+    Text:标签之间的文本
+    Comment:标签注释
+    DocumentFragment:文档片段 -->
+
+    <div>div1</div>
+    <div>div2</div>
+    <div class="haha"></div>
+    <form name="login"></form>
+    <div class="div1" id="mike"></div>
+    <p class="haha"></p>
+    <script>
+        //1.getElementsByTagName
+        var div1 = document.getElementsByTagName("div")[0]
+        console.log(div1);
+        
+        //2.getElementsByClassName
+        console.log(document.getElementsByClassName("haha")[0]);
+        
+        //3.getElementsByName
+        console.log(document.getElementsByName("login")[0]);
+        
+        //4.getElementById
+        console.log(document.getElementById("mike"));
+
+        //5.querySelector(".haha")
+        console.log(document.querySelector(".haha"))
+
+        //6.querySelectorAll(".haha")
+        console.log(document.querySelectorAll(".haha"));
+
+
+
+
+        //创建元素
+        var p = document.createElement("p");
+        var content = document.createTextNode("woshineirong");
+        var id = document.createAttribute("id");
+        id.value = "root "
+        p.appendChild(content);
+        p.setAttributeNode(id)  //只有在属性的添加是用
+        console.log(p);
+        var dd = document.getElementById("mike")
+        dd.appendChild(p)
+
+        //元素的属性
+        var d0 = document.getElementById("mike");
+        d0.id = "dd1"
+        d0.className = "dd0 dd1"
+        d0.classList.add("ss1")
+        console.log(d0.classList);
+        d0.classList.remove("ss1")
+        console.log(d0.classList);
+        
+        // innerHTML可以识别标签，而innerText会把标签识别为一个字符串
+        var str = "<a href = 'www.baidu.com'>baidu</a>"
+        //d0.innerText = str;           <a href = 'www.baidu.com'>baidu</a>
+        d0.innerHTML = str;
+        
+    </script>
+</body>
+
+</html>  
--- a/src/jsStudy/jsStudy.html
+++ b/src/jsStudy/jsStudy.html
@ -0,0 +1,71 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+
+<body>
+    <script>
+        var name = "nihao"
+        console.log(name.substr(1, 5));//ihao
+        console.log(name.substr(2, 3));//hao
+        console.log(name.substr(1));//ihao
+        console.log(name.substr(-2));//ao
+        console.log(name.substr(2, -1));//
+
+        // -1表示不匹配，若存在第二个参数，代表从该位置开始匹配
+        console.log(name.indexOf("ao"))
+        console.log(name.indexOf("ao", 4))
+
+        // 去掉字符串前后的空格，不改变原字符串，返回改变后的字符串
+        var str = "  haha nihaoa  "
+        var str1 = "  \nhaha nihaoa\r  "
+        console.log(str.trim())
+        console.log(str1.trim())
+
+        console.log("hahaha|woshi|ll".split("|"))//['hahaha', 'woshi', 'll']
+        console.log("hahaha,|woshi|,ll".split(","))//['hahaha', '|woshi|', 'll']
+        console.log("hahaha|woshi|ll".split("|",2))//['hahaha', 'woshi']
+
+        var arr = ["kalka","adj",1,"jajajaj"]
+        for(var i in arr){
+            console.log(arr[i])
+        }
+
+        console.log(Array.isArray(arr))//true   判断是否为数组
+
+        var arr1 = [];
+        arr1.push("nishishei?","woyebuzhidao")
+        console.log(arr1)
+        arr1.pop()
+        console.log(arr1)//['nishishei?']
+
+         console.log("==============")
+        console.log(arr.shift())// 删除开头第一个元素,并返回该元素     
+        arr.unshift("这是新的元素")//在开头添加一个元素
+        console.log(arr)
+
+        //数组方法join
+        var arr2 = [111,222,333,444]
+        var q = arr2.join("|")
+        console.log(q);
+        q=q.split("|")
+        console.log(q);
+
+        //cancat方法 数组合并
+        var arr3 = arr1.concat(arr2)
+        console.log(arr3);// ['nishishei?', 111, 222, 333, 444]
+
+        //reverse() 数组翻转，会改变原数组
+        console.log(arr3.reverse());//[444, 333, 222, 111, 'nishishei?']
+     
+        //indexOf()查询某字段在数组中的位置,若存在返回其索引，否则返回-1
+        console.log(arr2.indexOf(2));
+        
+    </script>
+</body>
+
+</html>