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What is the meaning of “$” sign in JavaScript可能重复:在JavaScript中“$”符号的含义是什么
Now this must seem to be an easy and stupid question to ask but I must know why we use the dollar ($
) symbol in jQuery and JavaScript. I always put a dollar in my scripts but I actuary don't know why.
现在这似乎是一个简单又愚蠢的问题,但我必须知道为什么我们在jQuery和JavaScript中使用美元($)符号。我总是在剧本里放一块钱,但我不知道为什么。
For an example:
一个例子:
$('#Text').click(function () {
$('#Text').css('color', 'red')
});
This just changes the text colour when you click it, but it demonstrates my point.
当你点击它的时候,它会改变文本的颜色,但是它展示了我的观点。
6 个解决方案
#1
47
In JavaScript it has no special significance (no more than a
or Q
anyway). It is just an uninformative variable name.
在JavaScript中,它没有什么特别的意义(至少不超过a或Q)。它只是一个无信息的变量名。
In jQuery the variable is assigned a copy of the jQuery
function. This function is heavily overloaded and means half a dozen different things depending on what arguments it is passed. In this particular example you are passing it a string that contains a selector, so the function means "Create a jQuery object containing the element with the id Text".
在jQuery中,为变量分配jQuery函数的副本。这个函数是重载的,这意味着有六个不同的东西取决于它被传递的参数。在这个特定的示例中,您将传递一个包含选择器的字符串,因此函数的意思是“创建一个包含id文本元素的jQuery对象”。
#2
37
The $
is just a function. It is actually an alias for the function called jQuery
, so your code can be written like this with the exact same results:
$只是一个函数。它实际上是jQuery函数的别名,所以你的代码可以这样写,结果完全相同:
jQuery('#Text').click(function () {
jQuery('#Text').css('color', 'red');
});
#3
9
The jQuery syntax is tailor made for selecting HTML elements and perform some action on the element(s).
jQuery语法是为选择HTML元素和对元素执行一些操作而定制的。
Basic syntax is: $(selector).action()
基本语法:$(选择).action()
A dollar sign to define jQuery A (selector) to "query (or find)" HTML elements A jQuery action() to be performed on the element(s)
将jQuery(选择器)定义为“查询(或查找)”的美元符号在元素上执行的jQuery动作()
更多关于这
#4
6
In jQuery, the $ sign it's just an alias to jQuery()
, then an alias to a function.
在jQuery中,$符号只是jQuery的别名(),然后是函数的别名。
This page reports:
这一页报告:
Basic syntax is: $(selector).action()
基本语法:$(选择).action()
- A dollar sign to define jQuery
- 定义jQuery的美元符号
- A (selector) to "query (or find)" HTML elements
- (选择器)到“查询(或查找)”HTML元素
- A jQuery action() to be performed on the element(s)
- 要在元素上执行的jQuery动作()
#5
3
The $
symbol simply invokes the jQuery library's selector functionality. So $("#Text")
returns the jQuery object for the Text
div
which can then be modified.
$符号仅仅调用jQuery库的选择器功能。因此,$(“#Text”)返回文本div的jQuery对象,然后可以对其进行修改。
#6
2
Additional to the jQuery thing treated in the other answers there is another meaning in JavaScript - as prefix for the RegExp properties representing matches, for example:
除了在其他答案中处理的jQuery之外,在JavaScript中还有另一个含义——作为表示匹配的RegExp属性的前缀,例如:
"test".match( /t(e)st/ );
alert( RegExp.$1 );
will alert "e"
会提醒“e”
But also here it's not "magic" but simply part of the properties name
但在这里,它并不是“魔法”,而是属性名的一部分
#1
47
In JavaScript it has no special significance (no more than a
or Q
anyway). It is just an uninformative variable name.
在JavaScript中,它没有什么特别的意义(至少不超过a或Q)。它只是一个无信息的变量名。
In jQuery the variable is assigned a copy of the jQuery
function. This function is heavily overloaded and means half a dozen different things depending on what arguments it is passed. In this particular example you are passing it a string that contains a selector, so the function means "Create a jQuery object containing the element with the id Text".
在jQuery中,为变量分配jQuery函数的副本。这个函数是重载的,这意味着有六个不同的东西取决于它被传递的参数。在这个特定的示例中,您将传递一个包含选择器的字符串,因此函数的意思是“创建一个包含id文本元素的jQuery对象”。
#2
37
The $
is just a function. It is actually an alias for the function called jQuery
, so your code can be written like this with the exact same results:
$只是一个函数。它实际上是jQuery函数的别名,所以你的代码可以这样写,结果完全相同:
jQuery('#Text').click(function () {
jQuery('#Text').css('color', 'red');
});
#3
9
The jQuery syntax is tailor made for selecting HTML elements and perform some action on the element(s).
jQuery语法是为选择HTML元素和对元素执行一些操作而定制的。
Basic syntax is: $(selector).action()
基本语法:$(选择).action()
A dollar sign to define jQuery A (selector) to "query (or find)" HTML elements A jQuery action() to be performed on the element(s)
将jQuery(选择器)定义为“查询(或查找)”的美元符号在元素上执行的jQuery动作()
更多关于这
#4
6
In jQuery, the $ sign it's just an alias to jQuery()
, then an alias to a function.
在jQuery中,$符号只是jQuery的别名(),然后是函数的别名。
This page reports:
这一页报告:
Basic syntax is: $(selector).action()
基本语法:$(选择).action()
- A dollar sign to define jQuery
- 定义jQuery的美元符号
- A (selector) to "query (or find)" HTML elements
- (选择器)到“查询(或查找)”HTML元素
- A jQuery action() to be performed on the element(s)
- 要在元素上执行的jQuery动作()
#5
3
The $
symbol simply invokes the jQuery library's selector functionality. So $("#Text")
returns the jQuery object for the Text
div
which can then be modified.
$符号仅仅调用jQuery库的选择器功能。因此,$(“#Text”)返回文本div的jQuery对象,然后可以对其进行修改。
#6
2
Additional to the jQuery thing treated in the other answers there is another meaning in JavaScript - as prefix for the RegExp properties representing matches, for example:
除了在其他答案中处理的jQuery之外,在JavaScript中还有另一个含义——作为表示匹配的RegExp属性的前缀,例如:
"test".match( /t(e)st/ );
alert( RegExp.$1 );
will alert "e"
会提醒“e”
But also here it's not "magic" but simply part of the properties name
但在这里,它并不是“魔法”,而是属性名的一部分