Today I had a strange experience when using a for loop in Java, which I really can't explain. That's my code snippet:
List<String[]> list;
....
for (String[] tmp : list.get(0)) {
...
}
This code snippet isn't compiling, because list.get(0) is returning a String an not an array of Strings. But why?
list.get(0) returns an array of Strings, so when you iterate over it, you are getting individual Strings:
for (String tmp : list.get(0)) {
...
}
If you iterate over the entire list, you will get a String array in each iteration:
for (String[] tmp : list) {
...
}
Try to iterate over arrays of string
for (String[] tmp : list) {
...
}
or to iterate over strings of first array
for (String tmp : list.get(0)) {
...
}
for (String[] tmp : list.get(0))
should be
for (String tmp : list.get(0))
since list.get(0) is an array of strings, not array of string arrays.
Actually, list.get(0) is not returning a String but a String[] as you expect. List<String[]> list is a List of String[]. list.get(0) therefore is a String[]. The problem is with your loop variable. If you loop over a String[], the type of the loop variable which holds a single element during the loop is just String.
It should be:
List<String[]> list;
// ...
for (String el : list.get(0)) {
// ...
}
When you are calling list.get(0), it is returning a String array. If I extend your code it becomes like below,
String[] strArr = list.get(0);
....
for (String[] tmp : strArr) { //compilation issue
...
}
Obviously which is wrong as each object inside strArr is String, not String array.
