这段WHILE语句怎么理解?while ((bytes = in.read(bteFile)) != -1){out.write(bteFile, 0, bytes);}JAVA中的,之前没见过这种.特别是这个条件判断((bytes = in.read(bteFile)) != -1)这个((bytes = in.read(bteFile))的意思是将值赋
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![这段WHILE语句怎么理解?while ((bytes = in.read(bteFile)) != -1){out.write(bteFile, 0, bytes);}JAVA中的,之前没见过这种.特别是这个条件判断((bytes = in.read(bteFile)) != -1)这个((bytes = in.read(bteFile))的意思是将值赋](/uploads/image/z/3690695-47-5.jpg?t=%E8%BF%99%E6%AE%B5WHILE%E8%AF%AD%E5%8F%A5%E6%80%8E%E4%B9%88%E7%90%86%E8%A7%A3%3Fwhile+%28%28bytes+%3D+in.read%28bteFile%29%29+%21%3D+-1%29%7Bout.write%28bteFile%2C+0%2C+bytes%29%3B%7DJAVA%E4%B8%AD%E7%9A%84%2C%E4%B9%8B%E5%89%8D%E6%B2%A1%E8%A7%81%E8%BF%87%E8%BF%99%E7%A7%8D.%E7%89%B9%E5%88%AB%E6%98%AF%E8%BF%99%E4%B8%AA%E6%9D%A1%E4%BB%B6%E5%88%A4%E6%96%AD%28%28bytes+%3D+in.read%28bteFile%29%29+%21%3D+-1%29%E8%BF%99%E4%B8%AA%28%28bytes+%3D+in.read%28bteFile%29%29%E7%9A%84%E6%84%8F%E6%80%9D%E6%98%AF%E5%B0%86%E5%80%BC%E8%B5%8B)
这段WHILE语句怎么理解?while ((bytes = in.read(bteFile)) != -1){out.write(bteFile, 0, bytes);}JAVA中的,之前没见过这种.特别是这个条件判断((bytes = in.read(bteFile)) != -1)这个((bytes = in.read(bteFile))的意思是将值赋
这段WHILE语句怎么理解?
while ((bytes = in.read(bteFile)) != -1)
{
out.write(bteFile, 0, bytes);
}
JAVA中的,之前没见过这种.
特别是这个条件判断
((bytes = in.read(bteFile)) != -1)
这个((bytes = in.read(bteFile))的意思是将值赋给bytes对吧,但是最外层又加了一堆括号是什么意思?表示的是里面赋值成功返回1么?为什么是-1?
应该理解成bytes = in.read(bteFile),然后看看byte的值是否等于-1么?
这段WHILE语句怎么理解?while ((bytes = in.read(bteFile)) != -1){out.write(bteFile, 0, bytes);}JAVA中的,之前没见过这种.特别是这个条件判断((bytes = in.read(bteFile)) != -1)这个((bytes = in.read(bteFile))的意思是将值赋
功能就是说按文件每行读取
直至读完为止
程序理解是:
bytes = in.read(bteFile)是个赋值语句
bytes最终就是in.read(bteFile)的值
in.read(bteFile)读到最后一行没有数据时返回-1
所以bytes就等于-1了
而bytes != -1是判断语句 判断是否读完文件
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也就是读文件常用的写法是这样
平时不建议这么写
程序可读性不好