var name = null;

The null value is special in that it is automatically converted to initial values of other data types. When used as a number it becomes 0, when used as a string it becomes "", and when used as a Boolean value it becomes false. Since the source of many JavaScript errors is uninitialized variables, one of the common debugging techniques is to initialize all new variables with a null value.

The JavaScript interpreter uses the null value on two occasions:

1. Built-in functions return null under certain circumstances.
2. Non-existent properties evaluate to null.

When checking for a null value, you should check if it is false:

if (!name) {

}

or if it is null:

if (name == null) {

}

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