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Logical operators are used to combine boolean expressions. Logical operators can be used to modify the results of comparisons. Typically, you will use a comparison operator to check a condition, and a logical operator to combine conditions into more complex logic.
Logical operators are used to determine the logic between variables or values.
Formula
Given that x = 6 and y = 3, the table below explains the logical operators:&&
Formula
(x < 10 && y > 1) is trueTry it » || OR (x === 5 || y === 5) is false Try it » !
!(x === y) is true Try it »
&& operator returns true if both expressions are true, otherwise false
let x = 6;
let y = 3;
let z = (x < 10 && y > 1)|| operator returns true if one or both expressions are true, otherwise false
let x = 6;
let y = -3;
let z = (x > 0 || y > 0)The NOT operator (!) returns true for false expressions and false for true expressions.
let x = (5 == 8);
let y = !(5 == 8)
The Nullish Coalescing Operator (??)?? operator returns the right operand when the left operand is nullish ( null or undefined ), otherwise it returns the left operand.
let name = null;
let text = "missing";
let result = name ?? text;When programming, a lot of values can be falsey (like 0, empty strings, false, undefined, null, NaN). However, sometimes you want to check if a variable is nullish (either undefined or null ), like when it is okay for a variable to be an empty string, or a false value. Then you can use the nullish coalescing operator.
?? is an ES2020 feature. ES2020 is fully supported in all modern browsers since
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