vim editing commands

vi instruction
Command mode:
    yy: copy the line where the cursor is located
    4yy: Copy the 4 lines down from the line where the cursor is located
    p: paste
    dd: cut the line where the cursor is located
    2dd: Cut the line where the cursor is located 2 lines down
    D: Cut from the current cursor to the end of the line
    d0: cut from the current cursor to the beginning of the line
    x: delete the current cursor, only one at a time
    X: delete the one in front of the current cursor, only one at a time
    h left j down k up l right
    H: the top of the current screen
    M: the middle of the current screen
    L: the bottom of the current screen
    ctrl+f---> page down one page of code
    ctrl+b---> turn up a page of code
    ctrl+d--->page down half a page of code
    ctrl+u---> turn up half a page of code
    20G: Quickly locate the second line of code
    G: Quickly return to the last line of the entire code
    gg: quickly go back to line 1 of the entire code
    w: skip backward by the length of a word, that is, adjust to the beginning of the next word
    b: skip forward the length of a word, that is, adjust to the beginning of the previous word
    u: undo the operation just now
    ctrl+r: reverse undo
    select a piece of code
    v:
    V:
    >>: move code to the right
    <<: move code to the left
    .: Repeat the last command
    r: replace a character
    R: replace the cursor and the following characters
    shift+zz: equivalent to wq
Last line mode:
    w: save
    q: quit
    wq: save and exit