lovecoding
/
Web1020


			
				
					
						
						
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							<!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>
        // 变量特性：随意转换变量类型 
        var a = 10;
        a = "hello";
        console.log(a);
        //变量特性：重复定义
        var a = "world";
        console.log(a);
        //变量特性：可以不定义直接使用 赋值操作
        b = "abc";
        console.log(b);

        //变量特性：可以定义不赋值
        var c;
        console.log(c);
        
        
    </script>
</body>
</html>