What does the val method in jquery do?

The val method in jquery is used to return or set the value attribute of the selected element; when used to return a value, this method returns the value of the value attribute of the first matching element, and its syntax is "$( selector).val()"; when used to set a value, this method sets the value of the value attribute of all matching elements, and its syntax is "$(selector).val(value)".

The operating environment of this tutorial: Windows 10 system, jquery version 3.2.1, Dell G3 computer.

What does the val method in jquery do?

val() method returns or sets the value attribute of the selected element.

When used to return a value:

This method returns the value of the value attribute of the first matching element.

When used to set a value:

This method sets the value of the value attribute of all matching elements.

Note: The val() method is typically used with HTML form elements.

Syntax

Return value attribute:

$(selector).val()

Set value attribute:

$(selector).val(value)

Set value attribute through function:

$(selector).val(function(index,currentvalue))

Parameter

value required. Specifies the value of the value attribute.

function(index,currentvalue) Optional. Specifies a function that returns the value to be set.

index - Returns the index position of the element in the collection.

currentvalue - Returns the current value of the selected element. The difference between

.html(), .text() and .val():

.html(), .text(), .val() three Both methods are used to read the content of the selected element; except that .html() is used to read the html content of the element (including html tags), and .text() is used to read the plain text content of the element, including Its descendant elements, .val() is used to read the "value" value of the form element. Among them, the .html() and .text() methods cannot be used on form elements, while .val() can only be used on form elements;

In addition, when the .html() method is used on multiple elements , only the first element is read; the .val() method is the same as .html(). If it is applied to multiple elements, only the "value" value of the first form element can be read, but the .text( ) is different from them. If .text() is applied to multiple elements, the text content of all selected elements will be read.

.html(htmlString), .text(textString) and .val(value) are all used to replace the content of the selected element. If the three methods are used on multiple elements at the same time, then Will replace the content of all selected elements. .html(), .text(), and .val() can all use the return value of the callback function to dynamically change the content of multiple elements.

Recommended learning: "jQuery Video Tutorial"

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