I am trying to create a regular expression that will capture JavaScript object properties, but I only want top level properties.
So for example I want to capture this.nodeName but I do not want to capture this.nodeName.length
I am trying the following expression: (this\.\w )(?!\.)
But the lookahead seems to be only working on the \w and not on the whole capture group and I don't understand why this is.
For example if I apply this(?!\.) to this. then it doesn't match thi, so I don't understand why capture groups seem to act differently.
Here is a demo of my expression
Perhaps someone more experienced in regular expression could help me out.
Thanks
CodePudding user response：
Try the following regex expression:
const captured = 'this.party.invitation'.match(/(?<captured>this\.\w*?)(\.|\n|$)/).groups.captured
console.log(captured)
?<captured> gives a name to the group (...). We use a group to capture our desired match. The regex expression also checks at the end if it ends in a dot, a new line (\n) or if it's the end of the line.
CodePudding user response：
You need to check the negative lookahead part first and then capture the following text if pattern is right. Change your regex to this,
(?!this\.\w \.)(this\.\w )