js 字符串对象的正则方法

<script type="text/javascript">
   var str = ‘javascript php 2021‘;
   var pattern = /\d+/;
   var res = str.match(pattern);
   console.log(res[0]);//2021
 
</script>

<script type="text/javascript">
   var str = ‘javascript php 2021‘;
   var pattern = /\d+/;
   var res = str.replace(pattern,‘2018‘);
   console.log(res);//javascript php 2018
 
</script>

<script type="text/javascript">
   var str = ‘javascript php 2021‘;
   var pattern = /\d+/;
   var res = str.search(pattern);
   console.log(res);//返回15起始位置
 
</script>

<script type="text/javascript">
   var str = ‘javascript php 2021‘;
   var pattern = / /;//按空格分割
   var res = str.split(pattern);
   console.log(res);//返回数组按空格分成三部分
 
</script>