Find Recurring Sequence in a Fraction | This function returns repeating sequence of a fraction . If repeating sequence doesn 't  exits, then returns empty String ; Initialize result ; Create a map to store already seen remainders . Remainder is used as key and its position in result is stored as value . Note that we need position for cases like 1 / 6. In this case , the recurring sequence doesn 't  start from first remainder. ; Find first remainder ; Keep finding remainder until either remainder becomes 0 or repeats ; Store this remainder ; Multiply remainder with 10 ; Append rem / denr to result ; Update remainder ; Driver program
function fractionToDecimal ( numr , denr ) { let res = " " ; let mp = new Map ( ) ; mp . clear ( ) ; let rem = numr % denr ; while ( ( rem != 0 ) && ( ! mp . has ( rem ) ) ) { mp . set ( rem , res . length ) ; rem = rem * 10 ; let res_part = Math . floor ( rem / denr ) ; res += res_part . toString ( ) ; rem = rem % denr ; } if ( rem == 0 ) return " " ; else if ( mp . has ( rem ) ) return res . substr ( mp . get ( rem ) ) ; return " " ; } let numr = 50 , denr = 22 ; let res = fractionToDecimal ( numr , denr ) ; if ( res == " " ) document . write ( " " ) ; else document . write ( " " + res ) ;