Js:多维数组文字声明:添加元素

Question

我想知道是否可以将元素广告到声明如下的数组中......请检查add（）函数，我不知道如何解决这个问题。谢谢

这不是必需的，但如果您给出一个解释，因为 c++ 观点程序员，我将不胜感激。

// My array is this way declared
var myArray = [
    ['John', 'Doe', '1980'],
    ['Jane','Malloy','1982'],
    ['Vincent','Malloy','1972']
];
// then I want to add a new elements in it, but It seems to doesn't work
var add = function() {
    
    //var textbox = document.getElementById('textbox').value;
    
    // storing new person in array
    myArray [3][0] = 'New1';
    myArray [3][1] = 'New2';
    myArray [3][2] = 'New3';
};
//finally this function is for displaying the elements of myArray
var show = function() {
    // clean output
    document.getElementById('output').innerHTML = '';
    // delay time
    setTimeout (function() {
    // showing info. people
        for (var i in myArray) {
            for (var j in myArray)
                document.getElementById('output').innerHTML += myArray[i][j] + ' ';
        
            document.getElementById('output').innerHTML += '<br/>';
        }
    }, 250);
};

Answer 1

所以就在这里：

var add = function() {
    //var textbox = document.getElementById('textbox').value;
    // storing new person in array
    myArray [3][0] = 'New1';
    myArray [3][1] = 'New2';
    myArray [3][2] = 'New3';
};

无法添加到myArray[3]，因为myArray[3]未定义。您需要先为myArray[3]分配一个空数组：

    myArray [3] = [];
    myArray [3][0] = 'New1';
    myArray [3][1] = 'New2';
    myArray [3][2] = 'New3';

或者更一般地说，假设这个想法是添加到数组的末尾，您可以执行以下操作：

 var idx = myArray.length;
 myArray[idx] = [];
 myArray[idx][0] = "New 1";
 // ...

甚至像这样：

var newArray = ["New1", "New2", "New3"];
myArray.push(newArray);