callbacks.has()

callbacks.has ( callback ) Returns: Booleanversion added: 1.7

  • callback
    Type: Function
    The callback to search for.

Description: Determine whether a supplied callback is in a list

Examples:

Example: Use callbacks.has() to check if a callback list contains a specific callback: 

// A sample logging function to be added to a callbacks list
var foo = function( value1, value2 ) {
  console.log( "Received: " + value1 + "," + value2 );
};

// A second function which will not be added to the list
var bar = function( value1, value2 ) {
  console.log( "foobar" );
};

var callbacks = $.Callbacks();

// Add the log method to the callbacks list
callbacks.add( foo );

// Determine which callbacks are in the list
console.log( callbacks.has( foo ) );
// true
console.log( callbacks.has( bar ) );
// false