是否可以通过例如对多个对象执行单个功能。将它们分组。我想做的是:
{object1, object2, object3}.toFront();
答案 0 :(得分:2)
一种简单的方法:
var nodes = [node.rectangle1, node.text, node.rectangle2];
for (var i = 0; i < nodes.length; i++) {
nodes[i].toFront();
}
如果您使用underscore并且简洁:
_.invoke([node.rectangle1, node.text, node.rectangle2], 'toFront');
如果您想要返回值,可以使用map,或者如果您只是需要一些额外的处理,请查看each。
编辑(完成此操作):你也可以使用内置forEach
(如果你不关心某些浏览器或者你选择填充它),其方式与下划线each
非常相似:
[node.rectangle1, node.text, node.rectangle2].forEach(function(el) {
el.toFront();
});
答案 1 :(得分:1)
虽然您已经接受了答案,但这可以通过JavaScript 1.6 / ECMAScript 5 th 版本以类似的方式实现:
function logElementID(element, index, array) {
var el = array[index],
prop = el.textContent ? 'textContent' : 'innerText';
el[prop] = el.id;
}
[document.getElementById('one'), document.getElementById('two')].forEach(logElementID);
或者通过扩展Object
原型:
function doStuff (el) {
console.log(el);
};
Object.prototype.actOnGroup = function(func){
var els = this.length ? this : [this];
for (var i = 0, len = els.length; i<len; i++){
func(els[i]);
}
return this;
};
document.getElementsByTagName('div').actOnGroup(doStuff);
document.getElementById('one').actOnGroup(doStuff);
或类似地,扩展Array
原型:
function doStuff (el) {
console.log(el);
};
Array.prototype.actOnGroup = function(func){
var els = this.length ? this : [this];
for (var i = 0, len = els.length; i<len; i++){
func(els[i]);
}
return this;
};
[document.getElementById('one'), document.getElementById('two')].actOnGroup(doStuff);
顺便提一下,如果您希望在没有(相对)最新JavaScript实施的情况下为用户提供forEach()
替代方案,则forEach()
的Mozilla开发人员网络页面提供以下内容: an]算法100%真实的ECMA-262,第5版':
// Production steps of ECMA-262, Edition 5, 15.4.4.18
// Reference: http://es5.github.com/#x15.4.4.18
if (!Array.prototype.forEach) {
Array.prototype.forEach = function forEach(callback, thisArg) {
var T, k;
if (this == null) {
throw new TypeError("this is null or not defined");
}
// 1. Let O be the result of calling ToObject passing the |this| value as the argument.
var O = Object(this);
// 2. Let lenValue be the result of calling the Get internal method of O with the argument "length".
// 3. Let len be ToUint32(lenValue).
var len = O.length >>> 0; // Hack to convert O.length to a UInt32
// 4. If IsCallable(callback) is false, throw a TypeError exception.
// See: http://es5.github.com/#x9.11
if ({}.toString.call(callback) !== "[object Function]") {
throw new TypeError(callback + " is not a function");
}
// 5. If thisArg was supplied, let T be thisArg; else let T be undefined.
if (thisArg) {
T = thisArg;
}
// 6. Let k be 0
k = 0;
// 7. Repeat, while k < len
while (k < len) {
var kValue;
// a. Let Pk be ToString(k).
// This is implicit for LHS operands of the in operator
// b. Let kPresent be the result of calling the HasProperty internal method of O with argument Pk.
// This step can be combined with c
// c. If kPresent is true, then
if (Object.prototype.hasOwnProperty.call(O, k)) {
// i. Let kValue be the result of calling the Get internal method of O with argument Pk.
kValue = O[k];
// ii. Call the Call internal method of callback with T as the this value and
// argument list containing kValue, k, and O.
callback.call(T, kValue, k, O);
}
// d. Increase k by 1.
k++;
}
// 8. return undefined
};
}
从MDN forEach()
文章的参考文献(下文)逐字复制; 2013年4月1日,14:30。
参考文献: