Referencia de sentencias de JavaScript
Declaraciones JavaScript
En HTML, las declaraciones de JavaScript son "instrucciones" que el navegador web debe "ejecutar".
Esta declaración le dice al navegador que escriba "Hola, Dolly". dentro de un elemento HTML con id="demo":
Ejemplo
document.getElementById("demo").innerHTML = "Hello Dolly.";
Para ver un tutorial sobre declaraciones, lea nuestro Tutorial de declaraciones de JavaScript .
Identificadores de declaraciones de JavaScript
Las declaraciones de JavaScript suelen comenzar con un identificador de declaración para identificar la acción de JavaScript que se va a realizar.
Los identificadores de declaraciones son palabras reservadas y no se pueden usar como nombres de variables (o cualquier otra cosa).
La siguiente tabla enumera todos los identificadores de declaraciones de JavaScript:
Statement | Description |
---|---|
break | Exits a switch or a loop |
class | Declares a class |
const | Declares a variable with a constant value |
continue | Breaks one iteration (in the loop) if a specified condition occurs, and continues with the next iteration in the loop |
debugger | Stops the execution of JavaScript, and calls (if available) the debugging function |
do ... while | Executes a block of statements and repeats the block while a condition is true |
for | Loops through a block of code a number of times |
for ... in | Loops through the properties of an object |
for ... of | Loops through the values of an iterable object |
function | Declares a function |
if ... else ... else if | Marks a block of statements to be executed depending on a condition |
let | Declares a variable |
return | Stops the execution of a function and returns a value from that function |
switch | Marks a block of statements to be executed depending on different cases |
throw | Throws (generates) an error |
try ... catch ... finally | Marks the block of statements to be executed when an error occurs in a try block, and implements error handling |
var | Declares a variable |
while | Marks a block of statements to be executed while a condition is true |