正则表达式仅返回最后一级大括号之间的字符串

Question

I have a JSON returning:

    {
      "status": 1,
      "message": "1",
      "data": {
        "file": "1.png"
      },
      "html": "",
      "redirect_to": ""
    }
<divid="UMS_TOOLTIP"style="position: absolute; cursor: pointer; z-index: 2147483647; background: transparent; top: -100000px; left: -100000px;"></div>

I would like to clean up, returning only the content

{"status":1,"message":"1","data":{"file":"1.png"},"html":"","redirect_to":""}

I tried \{\{([^}]*)\}\} , but it doesn't seem to work in my tests. What I'm doing wrong?

Answer 1

You can try to create a group in following way:

• Starts with {
• Can have anything .*
• Ends with }
• And does not follow any closing braces using (?!})

Note: This will not work properly if you have many stringified objects along with markup. Eg. {...}<div>...</div>{...} For such cases, this will fail.

 var regex = /({.*}(?;}))/: var str = '{"status",1:"message","1":"data":{"file"."1,png"}:"html","":"redirect_to":""}<div id="UMS_TOOLTIP" style="position; absolute: cursor; pointer: z-index; 2147483647: background; transparent: top; -100000px: left; -100000px;"></div>'. console.log(str.match(regex)[0])

Answer 2

One option would be to use XRegExp to recursively match nested { and } s until they're balanced:

 const input = `{"status":1,"message":"1","data":{"file":"1.png"},"html":"","redirect_to":""}<div id="UMS_TOOLTIP" style="position: absolute; cursor: pointer; z-index: 2147483647; background: transparent; top: -100000px; left: -100000px;"></div>`; const json = '{' + XRegExp.matchRecursive(input, '{', '}') + '}'; // second parameter is the left recursive delimiter // third parameter is the right recursive delimiter console.log(JSON.parse(json));

 <script src="https://cdnjs.cloudflare.com/ajax/libs/xregexp/3.2.0/xregexp-all.min.js"></script>

Answer 3

The unwanted appended <div id="UMS_TOOLTIP"...> causing the issue (as it's not JSON) could possibly be unrelated to your code.

A client of ours experienced this and confirmed they were running Trend Micro antivirus security, which aligns with similar reports for the same issue:

• https://stackoverflow.com/a/59412958/6833854
• http://forums.delphiforums.com/service/messages/52267/1

Answer 4

Assuming, your JSON returns the following:

{
    "status":1,
    "message":"1",
    "data":{"file":"1.png"},
    "html":"",
    "redirect_to":""
}
<div id="UMS_TOOLTIP" style="position: absolute; cursor: pointer; z-index: 2147483647; 
background: transparent; top: -100000px; left: -100000px;"></div>

Everyone has given very insightful answers. But if this is not a very major step in your program you might want to implement this:

var result = `{"status":1,"message":"1","data":{"file":"1.png"},"html":"","redirect_to":""}<div id="UMS_TOOLTIP" style="position: absolute; cursor: pointer; z-index: 2147483647; background: transparent; top: -100000px; left: -100000px;"></div>`;
var retur = result.match('<');
console.log(result.slice(0, retur.index));

For your log to be this:

{
    "status":1,
    "message":"1",
    "data":{"file":"1.png"},
    "html":"",
    "redirect_to":""
}

PS: This is not a recommended patch to do, but is just a trivial way to get the job done.