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JavaScript provides several built-in (built-in) datatypes. In addition to those, this page documents virtual types (virtual Class) like selectors, enhanced pseudo-types (pseudo class) like Events and all And everything wanted to know about Functions.
In addition to the built-in data types in native JS (built-in datatype), jquery also includes some extended data types (virtual types), such as selectors, events, and so on.
First, anything
The use of any virtual type in a jquery document indicates that any type can be used or should be expected.
Second, String
A string in JavaScript was an immutable (unchanging) object that contains none, one or many characters.
(1) var typeofstr = typeof "Hello World";//typeofstr is "string"
(2) Built-in method (built-in Methods):
"hello".charAt( 0 ) // "h""hello".toUpperCase() // "HELLO""Hello".toLowerCase() // "hello""hello".replace( /e|o/g, "x" ) // "hxllx""1,2,3".split( "," ) // [ "1", "2", "3" ](3) Length property: Returns the length of the character, such as "Hello". length returns 5
(4) A string is converted to Boolean: An empty string ("") defaults to False, and a non-empty string is true (such as "Hello").
Third, htmlstring
A string that is used to represent one or more DOM elements in a jquery document is specified as Htmlstring, which is typically created and inserted into the document. When passed as a parameter to the jquery () function, the string is started and parsed with <tag> until the last > character. Examples are as follows:
$( "<b>hello</b>" ).appendTo( "body" ); // <body><b>hello</b></body>$( "<b>hello</b>bye" ).appendTo( "body" ); // <body><b>hello</b></body>$( "bye<b>hello</b>" ).appendTo( "body" ); // 语法错误（Syntax error）， unrecognized expression: bye<b>hello</b>$( $.parseHTML( "bye<b>hello</b>" ) ).appendTo( "body" ); // <body>bye<b>hello</b></body>$( "<b>hello</b>wait<b>bye</b>" ).appendTo( "body" ); // <b>hello</b>wait<b>bye</b>:Iv. number
In native JavaScript, number is a 64-bit format IEEE 754 double precision (double-precision) value. Just as the string is immutable. All common operators are equivalent to the C language that can be applied to numbers (+,-, *,/,%, =, + =,-=, * =,/=, + +,--).
(1) The string is converted to boolean:if a number is zero and it defaults to false.
(2) Math, Math object:
Math. PI//3.141592653589793
Math. cos (MATH.PI)//-1
(3) parsing Numbers, converted to numbers: Parseint and Parsefloat methods
parseInt( "123" ) = 123 // (implicit decimal（十进制）)parseInt( "010" ) = 8 // (implicit octal（八进制）)parseInt( "0xCAFE" ) = 51966 // (implicit hexadecimal（十六进制）)parseInt( "010", 10 ) = 10 // (explicit decimal（十进制）)parseInt( "11", 2 ) = 3 // (explicit binary（二进制）)parseFloat( "10.10" ) = 10.1(4) Numbers to Strings, number converted to string
[1] When the number is glued to the (append) string, the string is obtained.
"" + 1 + 2; "12" "" + (1 + 2); "3" "" + 0.0000001; "1e-7" parseint ( 0.0000001); //1 (!)
[2] or with coercion type conversion:
String (1) + string (2); "A" String (1 + 2); "3"
(5) Nan and Infinity (Both nan and Infinity are of type "number"):
If the parseint method is called on a non-numeric string, Nan (not a number) is returned, and isNaN is commonly used to detect whether a variable is a numeric type, as follows:
parseInt( "hello", 10 ) // NaN isNaN( parseInt("hello", 10) ) // true
Infinity denotes infinity or infinity, such as 1/0//Infinity.
In addition Nan==nan returns false, but Infinity==infinity returns TRUE.
(6) Integer and float: is divided into the expression of integer and floating point type, are numeric types.
The Boolean: Boolean type, True or false.
Vi. Object Objects
Everything in JavaScript is object. The typeof operation on an object returns "Object".
var x = {}; var y = {name: "Pete", age:15};
For the Y object above, you can take a dot to get the property value, such as Y.name return "Pete", Y.age return 15
Jquery Types Summary
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