Passing
We know that java is pass-by-value, meaning that data is copied to the method parameters when we pass it to a method.
We can define methods with array variables as parameters.
public static void printArray(int[] array) {
// ...
}
We would call this method by passing an array reference.
intArr[0] = 0;
intArr[1] = 1;
intArr[2] = 1;
intArr[3] = 2;
intArr[4] = 3;
intArr[5] = 5;
printArray(intArr);
Java is still pass-by-value when we pass an array reference, but the array itself is not copied.
This would mean intArr and array are two different arrays. This is not the case.
Instead, the reference is copied. * Think of the reference like a street address. * Passing the reference to a method copies the street address into the method parameter. * The method now knows where the original array "lives" because it has a copy of the address.
This means that changes in the method will affect the original array.
However, assigning a new reference to the method parameter does not affect the original array.
Drill¶
Arrays/src/drills/ArrayReferences.java
* Call the changeArray method and pass the daysOfWeek array reference.
* Change Wednesday to "HUMPDAY" and Friday to "Viernes". (There is no need to iterate, just change the right index.)
* Reassign inputArr to a new array containing the values "Su", "M", "T", "W", "Th", "F", "Sa"
* Refactor the printing of the array into a method and pass it the daysOfWeek array reference.