How does JS get the value of input?-1024programmer

var inputEl = document.querySelector('[name="username"]');

 var val = inputEl. value;

 console.log(val);

input attribute HTML5

property	value	description
accept	mime_type	Specifies the type of file to submit via file upload.
align	left right top middle bottom	Deprecated. Specifies the alignment of the image input.
alt	text	Define the image input Alt text.
autocomplete	on off	Specifies whether to use the autocomplete function of the input field.
autofocus	autofocus	Determines whether the input field gets focus when the page loads. (not applicable to type=”hidden”)
checked	checked	Specifies that this input element should be selected when it is first loaded.
disabled	disabled	When the input element is loaded disable this element.
form	formname	Specifies one or more forms to which the input field belongs.
formaction	URL	Overrides the form’s action attribute. (for type=”submit” and type=”image”)
formenctype	see note	Overrides the form’s enctype attribute. (for type=”submit” and type=”image”)
formmethod	get post	overrides the method attribute of the form. (for type=”submit” and type=”image”)
formnovalidate	formnovalidate	Overrides the form’s novalidate attribute. If this attribute is used, no validation will be performed when the form is submitted.
formtarget	_blank _self _parent _top framename	Overrides the form’s target attribute. (for type=”submit” and type=”image”)
height	pixels %	Defines the height of the input field. (for type=”image”)
list	datalist-id	Reference contains input A datalist of predefined options for the field.
max	number date	Specifies the maximum value of the input field. Use with the “min” attribute to create a range of legal values.
maxlength	number	Specifies the maximum length of characters in the input field.
min	number date	Specifies the minimum value of the input field. Use with the “max” attribute to create a range of legal values.
multiple	multiple	If this attribute is used, more than one value is allowed.
name	field_name	Definition of the input element name.
pattern	regexp_pattern	Specifies the pattern or format of the value of the input field. For example, pattern=”[0-9]” means that the input value must be a number between 0 and 9.
placeholder	text	Specifies hints to help users fill out input fields.
readonly	readonly	specifies that the input field is read only.
required	required	Indicates that the value of the input field is required.
size	number_of_char	Define the input field width.
src	URL	Define to submit button The URL of the image displayed in the form.
step	number	specifies the legal number interval of the input word.
type	button checkbox file hidden image password radio reset submit text	Specifies the type of input element.
value	value	specifies the value of the input element.
width	pixels %	Define the width of the input field. (Applicable to type=”image”)