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5. The Head/Global Object > The Head Object Is Implied and Typically Not Refere...
The Head Object Is Implied and Typically Not Referenced Explicitly
Typically a reference to the head object is not used because it is
implied. For example, in the browser environment, window.alert and alert() are essentially the same statement.
JavaScript fills in the blanks here. Because the window object (i.e., the head object) is the
last object checked in the scope chain for a value, the window object is essentially always implied.
Below, we leverage the alert() function
which is contained in the global scope.
<!DOCTYPE html><html lang="en"><body><script>
var foo = { // window is implied here, window.foo
fooMethod: function() {
alert('foo' + 'bar'); // window is implied here, window.alert
window.alert('foo' + 'bar'); /* window is explicitly used,
with the same effect */
}
}
foo.fooMethod(); // window is implied here, window.foo.fooMethod()
</script></body></html>
