你可以用这个:

function getMeta(metaName) {
  const metas = document.getElementsByTagName('meta');

  for (let i = 0; i < metas.length; i++) {
    if (metas[i].getAttribute('name') === metaName) {
      return metas[i].getAttribute('content');
    }
  }

  return '';
}

console.log(getMeta('video'));

很简单，对吧?

document.head.querySelector("meta[property=video]").content

使用元根，然后获取和设置它的任何属性:

let meta = document.getElementsByTagName('meta')

console.log(meta.video.content)
> "http://video.com/video33353.mp4"

meta.video.content = "https://www.example.com/newlink"

function getDescription() {
    var info = document.getElementsByTagName('meta');
    return [].filter.call(info, function (val) {
        if(val.name === 'description') return val;
    })[0].content;
}

版本更新:

function getDesc() {
    var desc = document.head.querySelector('meta[name=description]');
    return desc ? desc.content : undefined;
}

你可以用这个:

function getMeta(metaName) {
  const metas = document.getElementsByTagName('meta');

  for (let i = 0; i < metas.length; i++) {
    if (metas[i].getAttribute('name') === metaName) {
      return metas[i].getAttribute('content');
    }
  }

  return '';
}

console.log(getMeta('video'));

如果您对获得所有元标记的更深远的解决方案感兴趣，可以使用这段代码

function getAllMetas() {
    var metas = document.getElementsByTagName('meta');
    var summary = [];
    Array.from(metas)
        .forEach((meta) => {
            var tempsum = {};
            var attributes = meta.getAttributeNames();
            attributes.forEach(function(attribute) {
                tempsum[attribute] = meta.getAttribute(attribute);
            });
            summary.push(tempsum);
        });
    return summary;
}

// usage
console.log(getAllMetas());