替换链接

function link() {
    let t = document.getElementById('jsContainer')
    let reg = /(https?:\/\/)?(www\.\w+(\.(com|cn))*([?]\w+=\w*(&\w+=\w*)*)?(#\w+)?)/g
    let textArr = []
    // 1.识别所有以http://、https://或者www.开始的链接
    textArr =t.innerHTML.match(reg)?Array.from(t.innerHTML.match(reg)): []
    // 2.添加链接标签
    textArr.forEach(item => {
      if (item.indexOf('www.') == 0) {
        t.innerHTML = t.innerHTML.replace(item, `<a href="http://${item}" target="_blank">${item}</a>`)
      } else {
        t.innerHTML = t.innerHTML.replace(item, `<a href="${item}"  target="_blank">${item}</a>`)
      }
    })
  }

示例

  function test1() {     
    var content = 'https';     
    var div = document.getElementById('jsContainer');     
    div.innerHTML = content;     
    link();     
    var result = div.innerHTML === content;     
    return result; 
  }
  function test2() {     
    var content = ' www.testhaha.com ';     
    var div = document.getElementById('jsContainer');     
    div.innerHTML = content;     
    link();     
    var aLink = div.getElementsByTagName('a') || [];
    var result = aLink.length === 1 && aLink[0].getAttribute('href') === 'http://www.testhaha.com' && aLink[0].getAttribute('target') === '_blank' && aLink[0].innerHTML === 'www.testhaha.com';     
    return result;
  }
    test1()
    test2()