改变输出流，windows下盘符应该这么写"D:\\Download\\300Demos\\Day4\\src\\log.txt"
Hello类中有各种方法
新增值传递和引用传递
Merge remote-tracking branch 'origin/master'

Conflicts:
	.idea/workspace.xml
	Day4/src/TernaryOperator.java
Merge remote-tracking branch 'origin/master'

Conflicts:
	.idea/workspace.xml
改变输出流，windows下盘符应该这么写"D:\\Download\\300Demos\\Day4\\src\\log.txt"