A conditional statement is a set of rules performed if a certain condition is met.

Warning: String.x is deprecated use programming languages provide flow control statements that allows you to control the order in which the code is executed.

Warning: JavaScript 1.6's for-each-in loops are deprecated.

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TypeError: setting getter-only property 'x'.

TypeError: property 'x' is non-configurable and can't be deleted.

TypeError: invalid assignment to const 'x'.

TypeError: invalid 'instanceof' operand 'x'.

TypeError: cannot use 'in' operator to search for 'x' in 'y'.

TypeError: can't redefine non-configurable property 'x'.

TypeError: can't delete non-configurable array element.

TypeError: can't define property 'x': 'obj' is not extensible.

TypeError: can't assign to property 'x' on 'y': not an object.

TypeError: can't access property 'x' of 'y'.

TypeError: X.prototype.y called on incompatible type.

TypeError: Reduce of empty array with no initial value.

TypeError: 'x' is not a non-null object.

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One common usage is to handle a value that may be null: let greeting = person => after property list Var beverage = (age >= 21) ? 'Beer' : 'Juice' If condition is any of these, the result of the conditional expression will be the result of executing the expression exprIfFalse.

Descriptionīesides false, possible falsy expressions are: null, NaN, 0, the empty string ( ''), and undefined.

exprIfFalse An expression which is executed if the condition is falsy (that is, has a value which can be converted to false). exprIfTrue An expression which is evaluated if the condition evaluates to a truthy value (one which equals or can be converted to true). Syntax condition ? exprIfTrue : exprIfFalse Parameters condition An expression whose value is used as a condition. If you'd like to contribute to the interactive examples project, please clone and send us a pull request. The source for this interactive example is stored in a GitHub repository.

Javascript conditional