Apply： 來源
function callMe(arg1, arg2){
var s = "";
s += "this value: " + this;
s += "<br>";
for (i in callMe.arguments) {
s += "arguments: " + callMe.arguments[i];
s += "<br />";
}
return s;
}
document.write("Original function: <br/>");
document.write(callMe(1, 2));
document.write("<br/>");
document.write("Function called with apply: <br/>");
document.write(callMe.apply(3, [ 4, 5 ]));
// Output:
// Original function:
// this value: [object Window]
// arguments: 1
// arguments: 2
// Function called with apply:
// this value: 3
// arguments: 4
// arguments: 5
Bind：來源
// 範例一
var checkNumericRange = function (value) {
if (typeof value !== 'number')
return false;
else
return value >= this.minimum && value <= this.maximum;
}
// The range object will become the this value in the callback function.
var range = { minimum: 10, maximum: 20 };
// Bind the checkNumericRange function.
var boundCheckNumericRange = checkNumericRange.bind(range);
// Use the new function to check whether 12 is in the numeric range.
var result = boundCheckNumericRange (12);
document.write(result);
// Output: true
// 範例二
// Create an object that contains the original function.
var originalObject = {
minimum: 50,
maximum: 100,
checkNumericRange: function (value) {
if (typeof value !== 'number')
return false;
else
return value >= this.minimum && value <= this.maximum;
}
}
// Check whether 10 is in the numeric range.
var result = originalObject.checkNumericRange(10);
document.write(result + " ");
// Output: false
// The range object supplies the range for the bound function.
var range = { minimum: 10, maximum: 20 };
// Create a new version of the checkNumericRange function that uses range.
var boundObjectWithRange = originalObject.checkNumericRange.bind(range);
// Check whether 10 is in the numeric range.
var result = boundObjectWithRange(10);
document.write(result);
// Output: true
// 範例三
// Define the original function with four parameters.
var displayArgs = function (val1, val2, val3, val4) {
document.write(val1 + " " + val2 + " " + val3 + " " + val4);
}
var emptyObject = {};
// Create a new function that uses the 12 and "a" parameters
// as the first and second parameters.
var displayArgs2 = displayArgs.bind(emptyObject, 12, "a");
// Call the new function. The "b" and "c" parameters are used
// as the third and fourth parameters.
displayArgs2("b", "c");
// Output: 12 a b c
Call：來源
function callMe(arg1, arg2){
var s = "";
s += "this value: " + this;
s += "<br />";
for (i in callMe.arguments) {
s += "arguments: " + callMe.arguments[i];
s += "<br />";
}
return s;
}
document.write("Original function: <br/>");
document.write(callMe(1, 2));
document.write("<br/>");
document.write("Function called with call: <br/>");
document.write(callMe.call(3, 4, 5));
// Output:
// Original function:
// this value: [object Window]
// arguments: 1
// arguments: 2
// Function called with call:
// this value: 3
// arguments: 4
// arguments: 5
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