current character is not greater than ch , then replace it with ch and increment ch
if ( s [ i ] . charCodeAt ( 0 ) <= ch . charCodeAt ( 0 ) ) { s [ i ] = ch ; ch = String . fromCharCode ( ch . charCodeAt ( 0 ) + 1 ) ; } } s = s . join ( ' ' ) if ( ch . charCodeAt ( 0 ) <= ' ' . charCodeAt ( 0 ) ) return false ; return true ; }