代码示例:(标识:eg_js_regexp_b)
<!DOCTYPE html>
<html>
<body>

<p>单击按钮可在字符串中单词的开头或结尾处对“W3”进行全局搜索。</p>

<button onclick="myFunction()">试一试</button>

<p id="demo"></p>

<script>
function myFunction() {
  var str = "Visit (www.sou-xun.com)s"; 
  var patt1 = /\bW3/g;
  var result = str.match(patt1);
  document.getElementById("demo").innerHTML = result;
}
</script>

</body>
</html>
运行结果: