我会比较char,但它实际上不起作用:比较CHAR变量在Java中
//...
System.out.print("PROCEED? (Y/N):\t");
line = in.nextLine();
ch = line.charAt(0);
while (ch != 'y' || ch != 'n' || ch != 'Y' || ch != 'N'){
System.out.print("NON-VALID INPUT. TYPE Y-N:\t");
line = in.nextLine();
ch = line.charAt(0);
}
//...
在我的终端,因为我按y
或n
,其结果是:
PROCEED? (Y/N): y
NON-VALID INPUT. TYPE Y-N: y
NON-VALID INPUT. TYPE Y-N: Y
NON-VALID INPUT. TYPE Y-N: n
NON-VALID INPUT. TYPE Y-N: r
NON-VALID INPUT. TYPE Y-N: d
...
'ch!='y'|| ch!='n''将总是*为真,因为如果'ch =='y''那么'ch!='n'';如果'ch =='n''那么'ch!='y'';如果'ch!='y''和'ch!='n''那么它也是如此。 –