Question

So, I want to built a regular expression that I can pass in a string of 0s and 1s (e.g. “0010101000111100100011110001101100011”) and then make sure that for every 6 consecutive characters, there needs to be at least two 1s in that block.

Also, strings less than length 6 should pass.

Examples of passing strings:

• “”
• “00”
• “11000011”
• “01010100”

Examples of failing strings:

• “110000000011”
• “000001”

These examples are of very small strings, but I want to build one to take any length string.

Now, I’m looking for a nice way to express this in a regular expression, rather than having solution with a loop and such.

Answer 1

Just use this regex and check that it doesn’t match:

/000000|000001|000010|000100|001000|010000|100000/