The && and || operators are called short-circuit operators. They will return the value of the second operand based on the value of the first operand.

The && operator is useful for checking for null objects before accessing their attributes. For example...

var name = person && person.getName();

This code is the same as

if(person) {
	var name = person.getName();
}

The || operator is used for setting default values.

var name = persons_name || "John Doe";

The equalant code is

if(persons_name) {
	var name = persons_name;
} else {
	var name = "John Doe";
}
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