question: protected final void putChar ( char ch ) { if ( sp == sbuf . length ) { char [ ] newsbuf = new char [ sbuf . length * 2 ] ; System . arraycopy ( sbuf , 0 , newsbuf , 0 , sbuf . length ) ; sbuf = newsbuf ; } sbuf [ sp ++ ] = ch ; }
target:  Append a character to sbuf.