What are the data types returned by typeof?

The data types that "typeof" can return are: "number", "string", "boolean", "undefined", "object", and "function". Typeof is an operator, the syntax is "typeof (expression)", it performs operations on expressions.

The data types that "typeof" can return are: "number", "string", "boolean", "undefined", "object" , "function".

typeof is an operator. There are two ways to use it: typeof (expression) and typeof variable name. The first is to operate on expressions, and the second is to operate on variables. Do calculations.

1. If it is a basic data type, return the corresponding basic type

1.number type

var num = 1;
        console.log(typeof num);//返回的是number

2.string type

        var str = 'jack';
        console.log(typeof str);//返回的是string

3. boolean type

    var boo =true;
        console.log(typeof boo);//返回的是boolean

4.undefined type

    var und ;
        console.log(typeof und);//返回的是undefined

2. If it is a complex data type

1. Array type

        var arr = new Array();
        console.log(typeof arr); //返回的是object
        // 2.function类型
        var fn = function(){};
        console.log(typeof fn); //返回的是function

3.Object type

        var  obj = new Object();
        var nul =null;（特别地）
        console.log(typeof nul); //返回的是object
        console.log(typeof obj); //返回的是object

4.Literal array

        var arr2 = [1,32];
        console.log(typeof arr2);//返回的是object

5.Customized object

    function Person(name){
            this.name =name;
        }
        var stu = new Person();
        console.log(typeof stu); //返回的是object
        // 可以得出：复杂数据类型，如果是对象，则返回的是object,如果的function类型,则返回的是function
        // 所以：typeof 可以返回的类型为：number、string、boolean、undefined、object、function

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