JS determines whether the data type is a string for the array, and so on

 js to determine whether a data type is an array type, judge whether it is a string type, determine whether it is a numeric type, and so on, this article has several good examples where you can learn

1 Determines whether the array type   2 determines whether the string type   3 determines whether the value type   4 determines whether the date type   5 Determines whether it is a function of   6 to determine whether the object is the     1 to determine whether the array Type     code is as follows: <script type= "Text/javascript" > //<! [cdata[  var a=[0];  document.write (IsArray (a), ' <br/> ');  function IsArray (obj) {  return ( typeof obj== ' object ') &&obj.constructor==Array; } //]]>  </script>    2 Determine if the string type   code is as follows: <script type= "Text/javascript" > //<! [cdata[  document.write (isstring (' Test '), ' <br/> ');  document.write (isstring, ' <br/> ');   function isstring (str) {  return (typeof str== ' string ') &&str.constructor==String; } // ]]>  </script>    3 to determine whether the numeric type   code is as follows: <script type= "Text/javascript" > //<! [cdata[  document.write (isnumber (' Test '), ' <br/> ');  document.write (isnumber, ' <br/> ');   function Isnumber (obj) {  return (typeof obj== ' number ') &&obj.constructor==Number; } //]]>  </script>    4 Determine if the date type   code is as follows: <script type= "Text/javascript" > //<! [cdata[  document.write (isDate (new Date), ' <br/> ');  document.write (IsDate (a), ' <br/> ');   function isDate (obj) {  return (typeof obj== ' object ') &&obj.constructor==Date; } //] >  </script>    5 to determine whether the function     code is as follows: <script type= "Text/javascript" > //< ! [cdata[  document.write (isfunction (function test () {}), ' <br/> ');  document.write (Isfunction (10), ' <br/> ');  function isfunction (obj) {  return (typeof obj== ' function ') &&obj.constructor== function; } //]]>  </script>    6 to determine whether the object   code is as follows: <script type= "text/ JavaScript "> //<! [cdata[  document.write (IsObject (new Object), ' <br/> ');  document.write (IsObject (10),' <br/> ');  function IsObject (obj) {  return (typeof obj== ' object ') &&obj.constructor==Object;  } //]]>  </script>