# Using code templates

In this section you will use content assist to fill in a template for a common loop structure. Open junit.samples/VectorTest.java file in the Java editor if you do not already have it open.

1. Start adding a new method by typing the following:

   `public void testValues() {
   Integer[] expected= new Integer[3];
   for
   `

2. With the cursor at the end of `for`, press `Ctrl+Space` to enable content assist. You will see a list of common templates for "for" loops. When you single-click a template, or select it with the `Up` or `Down` arrow keys, you'll see the code for the template in its help message. Note that the local array name is guessed automatically.

3. Choose the `for - iterate over array` entry and press `Enter` to confirm the template. The template will be inserted in your source code.

4. Next we change the name of the index variable from i to e. To do so simply press `e`, as the index variable is automatically selected. Observe that the name of the index variable changes at all places. When inserting a template all references to the same variable are connected to each other. So changing one changes all the other values as well.

5. Pressing the `tab` key moves the cursor to the next variable of the code template. This is the array expected.

   Since we don't want to change the name (it was guessed right by the template) we press tab again, which leaves the template since there aren't any variables left to edit.
6. Complete the `for` loop as follows:

   `for (int e= 0; e < expected.length; e++) {
   expected[e]= new Integer(e + 1);
   }
   Integer[] actual= to
   `

7. With the cursor at the end of `to`, press `Ctrl+Space` to enable content assist. Pick `toarray - convert collection to array` and press `Enter` to confirm the selection (or double-click the selection).

   The template is inserted in the editor and `type` is highlighted and selected.

8. Overwrite the selection by typing `Integer`. The type of array constructor changes when you change the selection.
9. Press `Tab` to move the selection to `collection` and overwrite it by typing `fFull`.

10. Add a semicolon and the following lines of code to complete the method:

    `assertEquals(expected.length, actual.length);
    for (int i= 0; i < actual.length; i++)
    assertEquals(expected[i], actual[i]);
    `

11. Save the file.

### Related concepts

Java editor
Templates

### Related references

Templates Preferences
Java Editor Preferences