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为什么将&&更改为| |会导致无法看到变量

while-loop loops file java

user8072194 · 技术社区 · 7 年前

我正在做一些阅读文件的练习,我的任务是为不平衡的文件编写文件交错代码。因此,如果我有这样的设置,它可以很好地工作:

while ((inputLine1 = LineSequential.read(inFileStreamName1)) != null **&&** (inputLine2 = LineSequential.read(inFileStreamName2)) != null)

注意(&A)&。。。但如果我将其更改为| | netbeans,则表明inputLine2尚未初始化(尽管它以这种方式看到inputLine1非常好):

while ((inputLine1 = LineSequential.read(inFileStreamName1)) != null **||** (inputLine2 = LineSequential.read(inFileStreamName2)) != null)

现在,如果inputLine1(这是来自文件A的数据)首先变为null,那么我只能每隔一行获取inputLine2(来自文件B)。在每次循环迭代中,它都会跳过一行。我很确定这与初始化inputLine2的位置有关

while ((inputLine1 = LineSequential.read(inFileStreamName1)) != null || LineSequential.read(inFileStreamName2) != null) {           
    inputLine2 = LineSequential.read(inFileStreamName2);
    System.out.println(inputLine2);
    if(inputLine1 != null && inputLine2 == null){
    LineSequential.write(outFileStreamName, inputLine1);
    }else if(inputLine1 == null && inputLine2 != null){
        LineSequential.write(outFileStreamName, inputLine2);
    }
    else if(inputLine1 != null && inputLine2 != null){
       LineSequential.write(outFileStreamName, inputLine1);
       LineSequential.write(outFileStreamName, inputLine2); 
    }
}