<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
    </head>
    <body>

        <script>
            const _searchStrIndexOf = (str, target) => {
                // 补全代码
                /*
                    1.用len存target的长度
                    2.使用indexOf判断第一次出现的索引
                    3.每找到一次num++，然后使用slice将前面部分切掉
                */
                var len = str.length
                var num = 0
                while(true){
                  var index = str.indexOf(target)
                  if(index !== -1){
                        str = str.slice(index + target.length)
                        num++
                  }else{
                      return num
                  }
                }
            }
        </script>
    </body>
</html>