4. Selector: filter elements (tags) with similar characteristics
1. Basic operation learning:
1. Event binding
//1. Get b1 button
$("#b1").click(function(){ alert("abc"); }); 2. Entry function $(function ( ) { }); The difference between window.onload and $(function) * window.onload can only be defined once, if it is defined multiple times, the latter will overwrite the former * $(function) can be defined multiple times. 3. Style control: css method // $("#div1").css("background-color","red"); $("#div1").css("backgroundColor","pink");
2. Classification
1. Basic selector
1. Tag selector (element selector)
* Syntax: $("html tag name") Get all the elements matching the tag name
2. id selector
* Syntax: $("#id的Attribute value") Get the element that matches the specified id attribute value
3. Class selector
* Syntax: $(".class attribute value") Get the element that matches the specified class attribute value
4. Union selector:
* Syntax : $("Selector1,Selector2....") Get all elements selected by multiple selectors
2. Hierarchical selector
1. Descendant selector
* Syntax: $("AB ") Select A element inside All B elements
2. Sub-selector
* Syntax: $("A> B") Select all B sub-elements inside A element
3. Attribute selector
1. Attribute name selector
* Syntax: $("A[attribute name]") contains the selector with the specified attribute
2. Attribute selector
* Syntax: $("A[attribute name='value']") contains the selector with the specified attribute equal to the specified value
3. Compound attribute selector
* Syntax: $("A[attribute name='value'][]...") A selector containing multiple attribute conditions
4. Filter selector
1. First element selector
* Syntax: :first Get the first element in the selected element
2. Last element selector
* Syntax: :last Get the last
element in the selected element 3. Non-element selector
* Syntax: :not(selector) does not include the specified content Element of
4. Even number selector
* Syntax: :even even number, counting from 0
5. Odd number selector
* Syntax: :odd odd number, counting from 0
6.Equal to index selector
* Syntax: :eq(index) specifies the index element
7. Greater than the index selector
* Syntax: :gt(index) is greater than the specified index element
8. Less than the index selector
* Syntax: :lt(index) is less than the specified index element
9. Title Selector
* Syntax: :header Get the heading (h1~h6) element, fixed writing
5. Form filter selector
1. Available element selector
* Syntax: :enabled Get available element
2. Unavailable element selector
* Syntax: :disabled Get the unavailable element
3. Select the selector
* Syntax: :checked Get the element selected by the radio/check box
4. Select the selector
* Syntax: :selected Get the element selected by the drop-down box