在javascript,jQuery或css中,如何扩展div或iframe以填充其余空间

div {
  height: 100%;
  width: 100%;
}

iframe {
  height: 100%;
  width: 100%;
}

document.getElementById("divID").style.height = "100%";
document.getElementById("divID").style.width = "100%";

document.getElementById("iframeID").style.height = "100%";
document.getElementById("iframeID").style.width = "100%";

$("#divID").css({
  "height": "100%",
  "width": "100%"
});

$("#iframeID").css({
  "height": "100%",
  "width": "100%"
});