if 2 erase s [ i ] and replace next with 7
s . splice ( i , 1 ) s [ i ] = ' ' ; } else if ( s [ i ] == ' ' ) s [ i ] = ' ' ; else if ( s [ i ] <= ' ' ) s [ i ] = ' ' ; else if ( s [ i ] <= ' ' ) s [ i ] = ' ' ; else s [ i ] = ' ' ; return s ; } function primeDigits ( s ) { for ( let i = 0 ; i < s . length ; i ++ ) {