js typeof 操作符

在js中 用typeof 操作符來檢測變量的數據類型

            var arr = [1,2,3,4,56,78];
            var str = 'student';
            var boer = true;
            var number = 18.99;
            console.log('數組',typeof arr)
            console.log('字符串',typeof str)
            console.log('布爾',typeof boer)
            console.log('數字',typeof number)
            console.log('對象',typeof window)
            console.log('null',typeof null)
            console.log('undefined',typeof undefined)
            console.log('function',typeof function fun(){})