jQuery基础

Basic Structure

$(document).ready(function(){
$(selector).event(function(){
$(selector).effect();
});
$(document).on('selector', 'event', function(){
$(selector).effect();
});
});

selector and select child\parent element

$('element_type')
$('.class')
$('#element_id')
$('selector:nth-child(4)')
$('selector:last-child(4)')
$('selector:even')
$('selector:odd')
$('selector').parent()
$(this)

event

- mouseenter(function(){})

- mouseleave(function(){})

- click()

- dblclick()

double click

- hover(inFunc, outFunc)

inFunction is required.

- focus()

- keydown() keypress() keyup()

keydown: the key is on its way down

keypress: the key is pressed down

keyup: the key is released

effect

- slideDown(‘fast’)

- slideToggle(‘slow’)

- fadeTo(‘fast’, 0.25)

- hide()

- fadeOut()

- fadeIn()

- animate()

input1: the animation to perform

input2: the time in which to perform the animation

$(document).ready(function() {
$('div').animate({left:'+=10px'},500);
//increasing the distance from the left margin moves something to the right
});

Modifying HTML Elements

- target.append(‘<p>element</p>’)

inserts the specified element as the last child of the target element.

- prepend()

inserts the specified element as the first child of the target element.

- appendTo(target)

- prependTo()

- move element

ele1.after(ele2);

ele1.before(ele2);

- empty()

deletes an element’s content and all its descendants

- remove()

not only deletes an element’s content, but deletes the element itself

- addClass()

- removeClass()

- toggleClass()

if the element has the class, it removes that class; if not, it adds the class.

- height(value) / width(value)

- css(CSS_element, value)

- html()

get/set html content

- val()

get the value of form element

$('input:checkbox:checked').val();
//Get the value from an input
var input = $('input[name=checkListItem]').val();

- clone()

- prop(property, value)

set element property.

There is also a method attr(), but I am quite confused about html attr vs. prop.

Using Ajax get and display json file example

getJSON()

$.getJSON("/json/cats.json", function(json) {
$(".message").html(JSON.stringify(json));
});

Convert Json data to HTML

var html = "";
json.forEach(function(val) {
var keys = Object.keys(val);
html += "<div class = 'cat'>";
keys.forEach(function(key) {
html += "<strong>" + key + "</strong>: " + val[key] + "<br>";
});
html += "</div><br>";
});
$(".message").html(html);