Concatenating Strings with Plus Operator spaces

Tell us what’s happening:
Why on earth is there a space after the dot after ‘start’, but no space after the dot after ‘end’?
It’s inconsistent and confusing. Is there any logical explanation for this?

Your code so far

// Example
var ourStr = "I come first. " + "I come second.";

// Only change code below this line

var myStr = "This is the start. " + "This is the end.";

Your browser information:

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Link to the challenge:

If you removed that space, concatenating the strings will result in

"I come first.I come second"

The space is there so the sentences are separated after concatenation.

Thank you. This was very helpful