I have inherited a Java program which I need to change. In one part of the code, I see I have created over 1000 String variables such as:
String field01
String field02
...
String field1000
I want to make a for loop to set all of the mentioned variables to "", but I am having issues with building a correct format for the for loop.
How do I create field+(i) in the for loop to set field01 to "" and the rest?
A for loop... Well, you could make this an array, but there's not really any way to make this into a for loop without an array.
Here's an example with one:
String[] test = new String[1000];
for (int number; numer < 1000; number++){
test[number] = "";
}
You have to use Reflection for doing the same.
class Test {
String field1
String field2
...
String field1000
}
public class FieldTest {
public static void main(String args[]) {
Test t = new Test();
Class cls = t.getClass();
for(int i=0 ; i<=1000; i++){
Field f1 = cls.getField("field"+i);
f1.set(t, "");
}
}
}
You can't really do this in Java. An alternative is to make a String array where the index of the array is the number of the variable that you want. So field01 would be stored in your string array at index 1.
First, create an array. Second, use Arrays.fill:
String[] fields = new String[1000];
Arrays.fill(fields, "");
Later you can access or modify individual variables by indices like fields[index].
Creating 1000 variables with similar names is not how people program in Java.
I know it is not the exact answer, but may help you.or you will need to use reflection.
Map<String, String> container = new HashMap<String, String>();
for (int i = 0; i <1000; i++) {
container.put("field"+ i, "\"\" ");
}
String field{n}with an array orList