With and without the quantifier {1} has same effect? [duplicate] - javascript

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Reference - What does this regex mean?
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Closed 4 years ago.
Is there any difference between the regular expressions:-
/^[1-9][0-9]+$/
and
/^[1-9]{1}[0-9]+$/
They both seem to give the same result. Which convention is better,because in many examples I can see the use of {1}, but feel it is quite useless, am I right?

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I have a string "str1+str2-str3*str4".
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If JS split lets capture groups become elements, then this should work
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using this
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EDIT
I don't believe this is duplicate. I know what a bitwise or is. I am specifically asking here why one might use it to or with a 0 before assignment. What purpose does that serve?
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Javascript regex to match string not preceded by [duplicate]

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