英文:
Counting the number of items in a file using java
问题
我有一个文本文件：
2|BATH BENCH|19.00
20|ORANGE BELL|1.42
04|BOILER ONION|1.78
我需要使用JAVA获取这里的项目数量，即3个项目。这是我的代码：
int Flag=0;
File file = new File("/Users/a0r01ox/Documents/costl-tablet-automation/src/ItemUPC/ItemUPC.txt");
Scanner sc = new Scanner(file);
while (sc.hasNextLine()) {
Flag=Flag+1;
}
它进入了一个无限循环。有人可以帮忙吗？谢谢。
英文:
I have a text file:
2|BATH BENCH|19.00
20|ORANGE BELL|1.42
04|BOILER ONION|1.78
I need to get the number of items which is 3 here using JAVA. This is my code:
int Flag=0;
File file = new File("/Users/a0r01ox/Documents/costl-tablet-automation/src/ItemUPC/ItemUPC.txt");
Scanner sc = new Scanner(file);
while (sc.hasNextLine()) {
Flag=Flag+1;
}
It is going in an infinite loop.
Can someone please help? Thank you.
答案1
得分: 1
你必须获取下一行以避免无限循环。
int Flag = 0;
File file = new File("/Users/a0r01ox/Documents/costl-tablet-automation/src/ItemUPC/ItemUPC.txt");
Scanner sc = new Scanner(file);
while (sc.hasNextLine()) {
sc.nextLine();
Flag++;
}
英文:
You must get the next line to avoid an endless loop.
int Flag = 0;
File file = new File("/Users/a0r01ox/Documents/costl-tablet-automation/src/ItemUPC/ItemUPC.txt");
Scanner sc = new Scanner(file);
while (sc.hasNextLine()) {
sc.nextLine();
Flag++;
}
答案2
得分: 1
while (sc.hasNextLine()) {
Flag=Flag+1;
String line = sc.nextLine(); //Do whatever with line
}
英文:
while (sc.hasNextLine()) {
Flag=Flag+1;
String line = sc.nextLine(); //Do whatever with line
}
答案3
得分: 1
代码中您编写了以下内容：
int Flag=0;
File file = new File("/Users/a0r01ox/Documents/costl-tablet-automation/src/ItemUPC/ItemUPC.txt");
Scanner sc = new Scanner(file);
while (sc.hasNextLine()) { // 这行代码是用来检查是否还有下一行。
Flag=Flag+1;
}
当您编写 while (sc.hasNextLine()){} 时，它会检查是否还有下一行。
例如：
第1行：abcdefg
第2行：hijklmnop
在这种情况下，您的代码将始终停留在 第1行，并不断告诉您存在下一行。
然而，当您编写：
while(sc.hasNextLine()){
sc.nextLine();
Flag++;
}
Scanner 将会读取 第1行，然后因为 sc.nextLine()，它将跳转到 第2行，然后当检查 sc.hasNextLine() 时，将返回 false。
英文:
In the code you have written
int Flag=0;
File file = new File("/Users/a0r01ox/Documents/costl-tablet-automation/src/ItemUPC/ItemUPC.txt");
Scanner sc = new Scanner(file);
while (sc.hasNextLine()) { // this line is just checking whether there is next line or not.
Flag=Flag+1;
}
When you write while (sc.hasNextLine()){} it check whether there is nextLine or not.
eg <br>line 1 : abcdefg<br>
line 2: hijklmnop<br>
here your code will just be on line 1 and keep telling you that yes there is a nextLine.<br>
Whereas when you write
while(sc.hasNextLine()){
sc.nextLine();
Flag++;
}
Scanner will read the line 1 and then because of sc.nextLine() it will go to line 2 and then when sc.hasNextLine() is checked it gives false.
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