JavaScript 2.0-The Complete Reference, Second ... - freecodingtutorial

Declare a function taking two arguments, which it will modify
function modifyValues(ref, prim)
{
}
ref[0] = "changed"; // modify the first argument, an array
prim = prim - 8; // modify the second, a number
// Invoke the function
modifyValues(refType, primType);
// Print the value of the reference type
document.writeln("The value of refType is: ", refType+"");
// Print the value of the primitive type
document.writeln("The value of primType is: ", primType);
The result is shown in Figure 6-3. Notice how the value of the reference type changed but the
value of the primitive type did not.
Figure 6-3: Reference variables can be changed within functions.
Comparing Objects
Another situation where you need to be careful with reference types (objects) is when
comparing them. When you use the equality (==) comparison operator, the interpreter
compares the value in the given variables. For primitive types, this means comparing the actual
data:
var str1 = "abc";
var str2 = "abc";