計算字串中某些關鍵字的出現次數

做個筆記，省的每次都忘記XD
<br /><br />//被搜尋的字串<br />str1="abcgdefgggg"<br />//關鍵字<br />key="gg"<br />document.write(CountKeyword(str1,key));<br />function CountKeyword(str,keyword){<br /> index = 0;<br /> count = 0;<br /> while (index!=-1){<br /> index = str.indexOf(keyword,index);<br /> if (index!=-1){<br /> index = index + keyword.length;<br /> count++;<br /> }<br /> }<br /> return count;<br />} <br />