<script>
  var str = '123sdfsdf456sdffs789'
  var numArr = str.match(/\d+/g)
  //直接输出
  console.log("直接输出："+numArr) // => ["123", "456", "789"]
  // 也可以把数字拼接起来
  console.log("拼接后输出："+numArr.join('')) // => 123456789
</script>

直接输出：123,456,789
拼接后输出：123456789

<script>
  var str = '123.456sdfsdf456.789'
  var numArr = str.match(/\d+\.\d+/g)

  console.log(numArr) / /=> ["123.456", "456.789"]
</script>