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This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The ParentNode.prepend method inserts a set of Node objects or DOMString objects before the first child of the ParentNode. DOMString objects are inserted as equivalent Text nodes.

Syntax

ParentNode.prepend(nodesToPrepend);

Parameters

nodesToPrepend
One or more nodes to insert before the first child node currently in the ParentNode. Each node can be specified as either a Node object or as a string; strings are inserted as new Text nodes.

Return value

undefined.

Exceptions

Examples

Prepending an element

var parent = document.createElement("div");
var p = document.createElement("p");
var span = document.createElement("span");
parent.append(p);
parent.prepend(span);

console.log(parent.childNodes); // NodeList [ <span>, <p> ]

Prepending text

var parent = document.createElement("div");
parent.append("Some text");
parent.prepend("Headline: ");

console.log(parent.textContent); // "Headline: Some text"

Appending an element and text

var parent = document.createElement("div");
var p = document.createElement("p");
parent.prepend("Some text", p);

console.log(parent.childNodes); // NodeList [ #text "Some text", <p> ]

ParentNode.prepend() is unscopable

The prepend() method is not scoped into the with statement. See Symbol.unscopables for more information.

var parent = document.createElement("div");

with(parent) { 
  prepend("foo");
}
// ReferenceError: prepend is not defined 

Polyfill

You can polyfill the prepend() method if it's not available:

// Source: https://github.com/jserz/js_piece/blob/master/DOM/ParentNode/prepend()/prepend().md
(function (arr) {
  arr.forEach(function (item) {
    if (item.hasOwnProperty('prepend')) {
      return;
    }
    Object.defineProperty(item, 'prepend', {
      configurable: true,
      enumerable: true,
      writable: true,
      value: function prepend() {
        var argArr = Array.prototype.slice.call(arguments),
          docFrag = document.createDocumentFragment();
        
        argArr.forEach(function (argItem) {
          var isNode = argItem instanceof Node;
          docFrag.appendChild(isNode ? argItem : document.createTextNode(String(argItem)));
        });
        
        this.insertBefore(docFrag, this.firstChild);
      }
    });
  });
})([Element.prototype, Document.prototype, DocumentFragment.prototype]);

Specification

Specification Status Comment
DOM
The definition of 'ParentNode.prepend()' in that specification.
Living Standard Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support54 No49 No3910
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support5454 ?4939106.0

See also

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このページの貢献者: ExE-Boss, merih, stevenwdv, CollinGrimm, Sheppy, jszhou, jpmedley, fscholz
最終更新者: ExE-Boss,