for

let str = "";

for (let i = 0; i < 9; i++) {
  str = str + i;
}

console.log(str);
// Expected output: "012345678"

for ([]; []; [ ])
  []

for (let i = 0; i < 9; i++) {
  console.log(i);
  //  - 
}

for (let i = "start" in window ? window.start : 0; i < 9; i++) {
  console.log(i);
}
// SyntaxError: 'for-in' loop variable declaration may not have an initializer.

//       
for (let i = ("start" in window ? window.start : 0); i < 9; i++) {
  console.log(i);
}

//  `in`   
for (let i = ("start" in window) ? window.start : 0; i < 9; i++) {
  console.log(i);
}

let i = 0;
for (; i < 9; i++) {
  console.log(i);
  //  
}

for (let i = 0; ; i++) {
  console.log(i);
  if (i > 3) break;
  //  - 
}

let i = 0;

for (;;) {
  if (i > 3) break;
  console.log(i);
  i++;
}

function showOffsetPos(id) {
  let left = 0,
    top = 0;

  for (
    let itNode = document.getElementById(id); // 
    itNode; // 
    left += itNode.offsetLeft,
      top += itNode.offsetTop,
      itNode = itNode.offsetParent //  
  ); //    ( )

  console.log(
    `   "${id}":
: ${left}px;
: ${top}px;`,
  );
}

showOffsetPos("content");

// :
//    "content":
// : 0px;
// : 153px;"