Regex to find if there is only one block of code

Question

My input is a string, I want to validate that there is only one first-level block of code.

Examples :

{ abc }              TRUE
{ a { bc }         


        

Answer 1

This is a terrible workaround.

Since this is in Javascript there's not really much to do, but please see the following regex:

/^{([^{}]*|{})*}$/

Where you copy ([^{}]*|{})* and insert it between the last pair of curly brackets (rinse and repeat). Every duplication of this pattern allows another level of nesting between your elements. (This is a workaround for the lack of recursion in JS regex, required to solve nesting problems.)

Online Regex Demo