- Source:
Methods
bind(thisArg, …argumentsopt) → {function}
- Source:
Creates a new function that, when called, has its this keyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called. Does not work with new funcA.bind(thisArg, args). MDN
Example
// Bind Scope
var module = {
x: 42,
getX: function () { return this.x; }
};
console.log(module.getX()); // Outputs: 42
var unboundGetX = module.getX;
console.log(unboundGetX()); // Outputs: undefined
// Because the function gets invoked at the global scope.
var boundGetX = unboundGetX.bind(module);
console.log(boundGetX()); // Outputs: 42
// Bind Argument
var addArguments = function (arg1, arg2) { return arg1 + arg2; };
addArguments(1, 2); // Returns: 3
var addThirtySeven = addArguments.bind(null, 37);
addThirtySeven(); // Returns: NaN. Because 37 + undefined
addThirtySeven(5); // Returns: 42. Because 37 + 5 = 42
addThirtySeven(5, 10); // Returns: 42. Because 10 is ingnored.Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
thisArg |
* | The value to be passed as the this parameter to the target function |
|
arguments |
* |
<optional> <repeatable> |
Arguments to prepend to arguments provided to the bound function |
Returns:
- A copy of the given function with the specified this value and initial arguments
- Type
- function