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Operador condicional (ternario)

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since julio de 2015.

El operador condicional (ternario) es el único operador en JavaScript que tiene tres operandos. Este operador se usa con frecuencia como atajo para la instrucción if.

In this article

Sintaxis

condición ? expr1 : expr2

Parámetros

condición

Una expresión que se evalúa como true o false.

expr1, expr2

Expresión con valores de algún tipo.

Descripción

Si la condición es true, el operador retorna el valor de la expr1; de lo contrario, devuelve el valor de expr2. Por ejemplo, para mostrar un mensaje diferente en función del valor de la variable isMember, se puede usar esta declaración:

js
"La Cuota es de: " + (isMember ? "$2.00" : "$10.00");

También puedes asignar variables dependiendo del resultado de la condición ternaria:

js
var elvisLives = Math.PI > 4 ? "Sip" : "Nop";

También es posible realizar evaluaciones ternarias múltiples (Nota: El operador condicional es asociativo):

js
var firstCheck = false, secondCheck = false, access = firstCheck ? "Acceso Denegado" : secondCheck ? "Acceso Denegado" : "Acceso Permitido"; console.log(access); // muestra "Acceso Permitido"

También puede usar operaciones ternarias en espacio vacío con el propósito de realizar diferentes operaciones:

js
var stop = false, age = 16; age > 18 ? location.assign("continue.html") : (stop = true);

También puede realizar más de una operación por caso, separándolas con una coma:

js
var stop = false, age = 23; age > 18 ? (alert("OK, puedes continuar."), location.assign("continue.html")) : ((stop = true), alert("Disculpa, eres menor de edad!"));

También puede realizar más de una operación durante la asignación de un valor. En este caso, el último valor separado por una coma del paréntesis será el valor asignado.

js
var age = 16; var url = age > 18 ? (alert("OK, puedes continuar."), // alert devuelve "undefined", pero será ignorado porque // no es el último valor separado por comas del paréntesis "continue.html") // el valor a ser asignado si age > 18 : (alert("Eres menor de edad!"), alert("Disculpa :-("), // etc. etc. "stop.html"); // el valor a ser asignado si !(age > 18) location.assign(url); // "stop.html"

Especificaciones

Specification
ECMAScript® 2027 Language Specification
# sec-conditional-operator

Compatibilidad con navegadores

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  1. JavaScript
  2. Tutorials and guides
  3. JavaScript Guide
    1. Introduction
    2. Grammar and types
    3. Control flow and error handling
    4. Loops and iteration
    5. Functions
    6. Expressions and operators
    7. Numbers and strings
    8. Representing dates & times
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    10. Indexed collections
    11. Keyed collections
    12. Working with objects
    13. Using classes
    14. Using promises
    15. JavaScript typed arrays
    16. Iterators and generators
    17. Resource management
    18. Internationalization
    19. JavaScript modules
  4. Intermediate
    1. Language overview
    2. JavaScript data structures
    3. Equality comparisons and sameness
    4. Enumerability and ownership of properties
    5. Closures
  5. Advanced
    1. Inheritance and the prototype chain
    2. Meta programming
    3. Memory Management
  6. References
  7. Built-in objects
    1. AggregateError
    2. Array
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    4. AsyncDisposableStack
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  8. Expressions & operators
    1. Adición (+)
    2. Asignación de adición (+=)
    3. Asignacion (=)
    4. Expresión de función asíncrona
    5. async function* expression
    6. await
    7. Bitwise AND (&)
    8. Bitwise AND assignment (&=)
    9. Bitwise NOT (~)
    10. Bitwise OR (|)
    11. Bitwise OR assignment (|=)
    12. Bitwise XOR (^)
    13. Bitwise XOR assignment (^=)
    14. expresión class
    15. Operador Coma
    16. Operador condicional (ternario)
    17. Decremento(--)
    18. Operador delete
    19. La desestructuración
    20. Division (/)
    21. Division assignment (/=)
    22. Comparación (==)
    23. Exponenciación (**)
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    25. function
    26. expresión function*
    27. Greater than (>)
    28. Greater than or equal (>=)
    29. Operador de agrupación
    30. import.meta
      1. import.meta.resolve()
    31. import()
    32. in
    33. Incremento (++)
    34. Inequality (!=)
    35. instanceof
    36. Left shift (<<)
    37. Left shift assignment (<<=)
    38. Less than (<)
    39. Less than or equal (<=)
    40. Operador lógico AND (&&)
    41. Logical AND assignment (&&=)
    42. Logical NOT (!)
    43. Operador lógico OR (||)
    44. Logical OR assignment (||=)
    45. Multiplicación (*)
    46. Multiplication assignment (*=)
    47. Operador new
    48. new.target
    49. null
    50. Nullish coalescing assignment (??=)
    51. Operador de coalescencia nula (??)
    52. Object initializer
    53. Precedencia de operadores
    54. Encadenamiento opcional
    55. Miembros
    56. Resto (%)
    57. Remainder assignment (%=)
    58. Right shift (>>)
    59. Right shift assignment (>>=)
    60. Sintaxis Spread
    61. Igualdad Estricta (===)
    62. Strict inequality (!==)
    63. Sustracción (-)
    64. Asignación de sustracción (-=)
    65. super
    66. this
    67. typeof
    68. Negación unaria (-=)
    69. Unario más (+)
    70. Unsigned right shift (>>>)
    71. Unsigned right shift assignment (>>>=)
    72. void
    73. yield
    74. yield*
  9. Statements & declarations
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  10. Functions
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  11. Classes
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  12. Regular expressions
    1. Backreference: \1, \2
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    16. Escapes de propiedades Unicode
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  13. Errors
    1. AggregateError: No Promise in Promise.any was resolved
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    24. SyntaxError: \ at end of pattern
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    27. SyntaxError: arguments is not valid in fields
    28. SyntaxError: await is only valid in async functions, async generators and modules
    29. SyntaxError: await/yield expression can't be used in parameter
    30. SyntaxError: cannot use ?? unparenthesized within || and && expressions
    31. SyntaxError: character class escape cannot be used in class range in regular expression
    32. SyntaxError: continue must be inside loop
    33. SyntaxError: duplicate capture group name in regular expression
    34. SyntaxError: duplicate formal argument x
    35. SyntaxError: for-in loop head declarations may not have initializers
    36. SyntaxError: function statement requires a name
    37. SyntaxError: functions cannot be labelled
    38. SyntaxError: getter and setter for private name #x should either be both static or non-static
    39. SyntaxError: getter functions must have no arguments
    40. SyntaxError: identifier starts immediately after numeric literal
    41. SyntaxError: illegal character
    42. SyntaxError: import declarations may only appear at top level of a module
    43. SyntaxError: incomplete quantifier in regular expression
    44. SyntaxError: invalid assignment left-hand side
    45. SyntaxError: invalid BigInt syntax
    46. SyntaxError: invalid capture group name in regular expression
    47. SyntaxError: invalid character in class in regular expression
    48. SyntaxError: invalid class set operation in regular expression
    49. SyntaxError: invalid decimal escape in regular expression
    50. SyntaxError: invalid identity escape in regular expression
    51. SyntaxError: invalid named capture reference in regular expression
    52. SyntaxError: invalid property name in regular expression
    53. SyntaxError: invalid range in character class
    54. SyntaxError: invalid regexp group
    55. SyntaxError: indicador de expresión regular no válido "x"
    56. SyntaxError: invalid unicode escape in regular expression
    57. SyntaxError: JSON.parse: bad parsing
    58. SyntaxError: label not found
    59. SyntaxError: missing : after property id
    60. SyntaxError: missing ) after argument list
    61. SyntaxError: missing ) after condition
    62. SyntaxError: missing ] after element list
    63. SyntaxError: missing } after function body
    64. SyntaxError: missing } after property list
    65. SyntaxError: missing = in const declaration
    66. SyntaxError: missing formal parameter
    67. SyntaxError: missing name after . operator
    68. SyntaxError: missing variable name
    69. SyntaxError: negated character class with strings in regular expression
    70. SyntaxError: new keyword cannot be used with an optional chain
    71. SyntaxError: nothing to repeat
    72. SyntaxError: numbers out of order in {} quantifier.
    73. SyntaxError: octal escape sequences can't be used in untagged template literals or in strict mode code
    74. SyntaxError: parameter after rest parameter
    75. SyntaxError: private fields can't be deleted
    76. SyntaxError: property name __proto__ appears more than once in object literal
    77. SyntaxError: raw bracket is not allowed in regular expression with unicode flag
    78. SyntaxError: redeclaration of formal parameter "x"
    79. SyntaxError: reference to undeclared private field or method #x
    80. SyntaxError: rest parameter may not have a default
    81. SyntaxError: return not in function
    82. SyntaxError: setter functions must have one argument
    83. SyntaxError: string literal contains an unescaped line break
    84. SyntaxError: super() is only valid in derived class constructors
    85. SyntaxError: tagged template cannot be used with optional chain
    86. SyntaxError: Unexpected '#' used outside of class body
    87. SyntaxError: Unexpected token
    88. SyntaxError: unlabeled break must be inside loop or switch
    89. SyntaxError: unparenthesized unary expression can't appear on the left-hand side of '**'
    90. SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
    91. SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
    92. TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed
    93. TypeError: 'x' is not iterable
    94. TypeError: "x" is (not) "y"
    95. TypeError: "x" is not a constructor
    96. TypeError: "x" is not a function
    97. TypeError: "x" is not a non-null object
    98. TypeError: "x" is read-only
    99. TypeError: already executing generator
    100. TypeError: BigInt value can't be serialized in JSON
    101. TypeError: calling a builtin X constructor without new is forbidden
    102. TypeError: can't access/set private field or method: object is not the right class
    103. TypeError: can't assign to property "x" on "y": not an object
    104. TypeError: can't convert BigInt to number
    105. TypeError: can't convert x to BigInt
    106. TypeError: can't define property "x": "obj" is not extensible
    107. TypeError: can't delete non-configurable array element
    108. TypeError: can't redefine non-configurable property "x"
    109. TypeError: can't set prototype of this object
    110. TypeError: can't set prototype: it would cause a prototype chain cycle
    111. TypeError: cannot use 'in' operator to search for 'x' in 'y'
    112. TypeError: class constructors must be invoked with 'new'
    113. TypeError: cyclic object value
    114. TypeError: derived class constructor returned invalid value x
    115. TypeError: getting private setter-only property
    116. TypeError: Initializing an object twice is an error with private fields/methods
    117. TypeError: invalid 'instanceof' operand 'x'
    118. TypeError: invalid Array.prototype.sort argument
    119. TypeError: invalid assignment to const "x"
    120. TypeError: Iterator/AsyncIterator constructor can't be used directly
    121. TypeError: matchAll/replaceAll must be called with a global RegExp
    122. TypeError: More arguments needed
    123. TypeError: null/undefined has no properties
    124. TypeError: property "x" is non-configurable and can't be deleted
    125. TypeError: Reduce of empty array with no initial value
    126. TypeError: setting getter-only property "x"
    127. TypeError: WeakSet key/WeakMap value 'x' must be an object or an unregistered symbol
    128. TypeError: X.prototype.y called on incompatible type
    129. URIError: malformed URI sequence
    130. Warning: -file- is being assigned a //# sourceMappingURL, but already has one
    131. Warning: unreachable code after return statement
  14. Misc
    1. JavaScript technologies overview
    2. Execution model
    3. Lexical grammar
    4. Iteration protocols
    5. Strict mode
    6. Template literals
    7. Trailing commas
    8. Deprecated features

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