[英]Javascript: best way to instantiate an array of objects
最簡單的方法是使用構造函數創建的大量對象填充數組?
我有一個構造函數,而不是制作電視和電影對象:
function Media(name, boxCover) {
this.name = name;
this.boxCover = boxCover;
};
我正在制作要放入數組的許多對象。 這不起作用:
var table = [
var avengers = new Media("avengers",'../assets/boxcovers/avengers.jpg');
var blade_runner = new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg');
var brave = new Media("brave",'../assets/boxcovers/brave.jpg');
var catching_fire = new Media("catching_fire",'../assets/boxcovers/catching_fire.jpg');
var django = new Media("django",'../assets/boxcovers/django.jpg');
var finding_nemo = new Media("finding_nemo",'../assets/boxcovers/finding_nemo.jpg');
];
我也嘗試過將table.push(
放在每一行的開頭。我是否真的需要像這樣在數組中再次列出每個對象,否則我可以省去重復的工作:
table = [avengers, blade_runner, etc.
語法將是
var table = {
mykey: myproperty,
mykey2: myproperty2
};
如果希望變量成為對象,即可以通過調用fe table.avengers
來訪問屬性,則聲明應類似於:
var table = {
avengers: new Media("avengers",'../assets/boxcovers/avengers.jpg'),
blade_runner: new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg'),
brave: new Media("brave",'../assets/boxcovers/brave.jpg')
//... and so on and so forth
};
如果只希望能夠遍歷它們,則可以將其創建為數組:
var table = [
new Media("avengers",'../assets/boxcovers/avengers.jpg'),
new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg'),
new Media("brave",'../assets/boxcovers/brave.jpg')
//... and so on and so forth
];
您使用了錯誤的語法。 嘗試以下方法:
function Media(name, boxCover) {
this.name = name;
this.boxCover = boxCover;
};
var table = [
new Media('avengers','../assets/boxcovers/avengers.jpg'),
new Media('blade_runner','../assets/boxcovers/blade_runner.jpg')
];
您還可以使用簡單的語法,例如:
var mediatable = [];
var entry = {
name: {},
boxCover: {}
};
mediatable.push({
name: "avengers",
boxCover: '../assets/boxcovers/avengers.jpg'
});
mediatable.push({
name: "blade_runner",
boxCover: '../assets/boxcovers/blade_runner.jpg'
});
alert(mediatable.length);
或使用對象將其推送:
entry.name = "brave";
entry.boxCover = '../assets/boxcovers/brave.jpg';
mediatable.push(entry);
alert(mediatable.length + ":" + mediatable[1].name);
function Media(name, boxCover) {
this.name = name;
this.boxCover = boxCover;
};
function MediaTable(data) {
var table = {};
data.forEach(function(el){
table[el[0]] = new Media(el[0], el[1])
})
return table;
};
var tableData = [
["avengers", '../assets/boxcovers/avengers.jpg'],
["blade_runner", '../assets/boxcovers/blade_runner.jpg'],
["brave" , '../assets/boxcovers/brave.jpg'],
["catching_fire", '../assets/boxcovers/catching_fire.jpg'],
["django", '../assets/boxcovers/django.jpg'],
["finding_nemo", '../assets/boxcovers/finding_nemo.jpg']
],
table = new MediaTable(tableData);
像這樣重寫您的var表 ,這一切都需要:
var table = [
new Media("avengers",'../assets/boxcovers/avengers.jpg'),
new Media("blade_runner",'../assets/boxcovers/blade_runner.jpg'),
new Media("brave",'../assets/boxcovers/brave.jpg'),
new Media("catching_fire",'../assets/boxcovers/catching_fire.jpg'),
new Media("django",'../assets/boxcovers/django.jpg'),
new Media("finding_nemo",'../assets/boxcovers/finding_nemo.jpg')
];
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