jQuery selectors can be grouped into the following categories:

• Basic selector: Selects elements based on basic criteria such as ID, CSS class, and
HTML tag name.
• Basic filter: Filters an element set based on conditions such as first occurrence, last
occurrence, and odd or even elements.
• Attribute selector: Selects elements by matching their attribute values.
• Child filter: Filters an element set based on conditions such as first-child, last-child,
nth-child, and only-child.
• Content filter: Filters elements based on their content.
• Form selector: Selects form elements based on their type (button, check box, and so
on) and state (selected or checked).
• Hierarchy selector: Selects elements from a hierarchy (children, descendents,
siblings, and adjacent).

• Visibility filter: Selects elements based on their visibility status (visible or hidden).

这个写得很好，给需要的朋友