show scrollbar only when overflow code example

Example 1: scrollbar appear only when needed

overflow: auto

Example 2: css show scrollbar if overflow

/*You can automatically show a scrollbar IF there is overflow with  this: */
body {
  overflow:auto;
}
/*If you want to always show a scrollbar, use this: */
body {
  overflow:scroll;
}

Example 3: show scroll only when overflow

overflow: auto;