null line

基本解釋

If not NULL, increment the line counter.
如果不是 NULL，則增加行計(jì)數(shù)器。
A serial line (null-modem cable) connects the machines through their serial ports.
一條串行線(xiàn)（空調(diào)制解調(diào)器電纜）將通過(guò)機(jī)器的串口連接它們。
When you modify the SimpleTask[] tasks = null; (line 2 in Listing 12) to SimpleTask[] tasks = new SimpleTasks[0];, you will only need to write Listing 13 to look like
當(dāng)您將 SimpleTask[] tasks = null;（清單 12 中的第 2 行）修改為 SimpleTask[] tasks = new SimpleTasks[0]; 時(shí)，您只需將清單 13 編寫(xiě)為