Name
|| — NN 2 IE J1 ECMA 1
Synopsis
The OR operator. This operator compares two Boolean expressions for
equality. If either or both expressions evaluate to
true
, the result of the || operator also evaluates
to true
; if both expressions are
false
, the ||
operator
evaluates to false
. A Boolean expression may
consist of a comparison expression (using any of the many comparison
operators) or a variety of other values. See the discussion of the
AND operator for a summary of the most common data types, values, and
their Boolean value equivalent.
You can create compound conditions with the help of the
&&
operator. For example, if you want to
see if either or both of two conditions are true, you would create a
condition such as the following:
var userEntry1 = document.forms[0].entry1.value var userEntry2 = document.forms[0].entry2.value if (userEntry1 || userEntry2) { ... }
In the compound condition, the ||
operator wants
to know if either or both operands is true
before
it evaluates to true
. If the user entered text
into the first field, the condition short-circuits because a
true
value of either operand yields a
true
result. If text were entered only in the
second field, the second operand is evaluated. Because it evaluates
to true
(a nonempty string), the condition
evaluates to true
. Only when both operands
evaluate to false
does the compound condition
evaluate to false
.
Example
if (a <= b || b >= c) { ... }
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