jquery css remove px

jQuery is a very popular JavaScript library that can easily manipulate HTML documents and CSS styles. By using jQuery, you can easily add, delete, modify and query CSS styles, making the design of web pages more flexible and diverse.

In front-end development, the operation of CSS styles is often used. One of the common requests is to remove the "px" unit from CSS styles. Many times we need to convert CSS style values ​​into numbers without units, so that we can use these numbers for calculations and comparisons.

In jQuery, there are many ways to achieve this function. Here are some common methods.

1. Using the parseInt() function

The parseInt() function is a built-in function of JavaScript, used to parse strings and return integers. For CSS values ​​with "px" units, you can use the parseInt() function to remove the units, resulting in a number.

For example, there is an element with a width of "100px", we can use the following code to convert it to a number without units:

var width = parseInt($("#element").css("width"));

In this example, we first use jQuery The selector selects an element, and then uses the .css() method to obtain the CSS style value of the element. Finally, use the parseInt() function to convert the value to an integer. This way you can get the width value without units.

2. Use the parseFloat() function

In addition to the parseInt() function, there is another common JavaScript built-in function called parseFloat(). What it does is parse a string and return a floating point number. For CSS values ​​with decimal points and "px" units, you can use the parseFloat() function to remove the units, resulting in a number.

For example, if there is an element with an opacity of "0.5", we can use the following code to convert it to a number without a unit:

var opacity = parseFloat($("#element").css("opacity"));

In this example, we also use jQuery The selector selects an element, and then uses the .css() method to obtain the CSS style value of the element. Finally, use the parseFloat() function to convert the value to a floating point number. This way you can get the transparency value without units.

3. Using regular expressions

In addition to using JavaScript built-in functions, you can also use regular expressions to remove units in CSS styles. Regular expressions are a powerful pattern matching tool that can easily identify specific patterns in strings.

For example, to convert "100px" to a number without units, you can use the following code:

var num = "100px".replace(/D+/g, '');

In this example, we used the .replace() method to replace the string The "px" unit in . This method requires two parameters: what to replace and what to replace it with. In this example, we used the regular expression /D /g to match all non-numeric characters in a string and replace them with the empty string. This way you can get numbers without units.

4. Use class library plug-in

If you are not familiar with regular expressions, or want a simpler way to remove units in CSS styles, you can consider using classes library plugin. jQuery has many excellent plug-ins, some of which are specifically designed to handle CSS styles.

For example, you can use the jquery-unitize plug-in to remove units from CSS styles. You can first introduce the plug-in into your HTML file, and then use the following code to remove the "px" unit in "100px":

var num = $.unitize("100px");

In this example, we first use the $.unitize() function to remove the "px" unit and assign the returned value to the variable num. This way you can get numbers without units.

Summary

No matter which method is used, removing the "px" unit from CSS styles is very simple. JavaScript and jQuery provide many convenient tools and functions to make front-end development more convenient. In actual development, you can choose the method that best suits you to implement the function according to your needs.

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