How to determine if jquery is a string

Jquery method to determine whether it is a string: 1. Determine it as a string type, the code is [alert((typeof str=='string')&&str.constructor==String)]; 2. Determine it as Array type, the code is [alert((typeof..].

The operating environment of this tutorial: windows7 system, jquery3.2.1 version, Dell G3 computer, the The method is applicable to all brands of computers.

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jquery method to determine whether it is a string:

1. Determine whether it is a string type

var str="ss";
alert((typeof str=='string')&&str.constructor==String)

2. Determine whether it is an array type

var obj=[0];
alert((typeof obj=='object')&&obj.constructor==Array)

Method 2

function isString(obj){ //判断对象是否是字符串  
   return Object.prototype.toString.call(obj) === "[object String]";  
}  
验证：
var str1 = 'abc';
var str2 = new String('abc');
 
typeof str1; //"string"
typeof str2; //"object"
Object.prototype.toString.call(str1); //"[object String]"
Object.prototype.toString.call(str2); //"[object String]"

3. Determine whether it is a numeric type

var str=547.97;
alert((typeof str=='number')&&str.constructor==Number)

4. Determine whether it is a date type

var obj =new Date();
alert((typeof obj=='object')&&obj.constructor==Date)

5. Determine whether it is a function

var obj = function test(){};
alert((typeof obj=='function')&&obj.constructor==Function)

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