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The conditional (ternary) operator is the only JavaScript operator that takes three operands: a condition followed by a question mark (?), then an expression to execute if the condition is true followed by a colon (:), and finally the expression to execute if the condition is false
This operator is often used as an alternative to theif...else statement.
Syntax
condition ? expressionTrue : expressionFalse
Parameters
condition- An expression whose value is used as a condition.
expressionTrue- An expression which is executed if the
conditionevaluates to a true value (one which equals or can be converted totrue). expressionFalse- An expression which is executed if the
conditionis false (that is, has a value which can be converted tofalse).
Besides false, possible false expressions are: null, NaN, 0, the empty string (""), and undefined. If condition is any of these, the result of the conditional expression will be the result of executing the expression expressionFalse.
Examples
let passMark = 49; let message; passMark >= 50 ? (message = 'You passed the test.') : (message = 'You failed the test.'); console.log(message);
Output:
You failed the test
Using multiple JavaScript ternary operators example
The following example shows how to use two ternary operators in the same expression
let speed = 70; let message = speed >= 120 ? 'Too Fast' : speed >= 60 ? 'Fast' : 'OK'; console.log(message);