到目前为止，我找到的所有文档都是更新已经创建的密钥：
arr['key'] = val;
我有一个像这样的字符串：" name = oscar "
我想得到像这样的结果：
{ name: 'whatever' }
即将字符串拆分并获取第一个元素，然后将其放入字典中。
var text = ' name = oscar '
var dict = new Array();
var keyValuePair = text.split(' = ');
dict[ keyValuePair[0] ] = 'whatever';
alert( dict ); // Prints nothing.
new Array()，这对于一个简单的关联数组（也称为字典）来说是过度杀伤力（和开销）。new Object()。它可以正常工作，但为什么要多打那么多字呢？// Create an empty associative array (in JavaScript it is called ... Object)
var dict = {}; // Huh? {} is a shortcut for "new Object()"
// Add a key named fred with value 42
dict.fred = 42; // We can do that because "fred" is a constant
// and conforms to id rules
// Add a key named 2bob2 with value "twins!"
dict["2bob2"] = "twins!"; // We use the subscript notation because
// the key is arbitrary (not id)
// Add an arbitrary dynamic key with a dynamic value
var key = ..., // Insanely complex calculations for the key
val = ...; // Insanely complex calculations for the value
dict[key] = val;
// Read value of "fred"
val = dict.fred;
// Read value of 2bob2
val = dict["2bob2"];
// Read value of our cool secret key
val = dict[key];
现在让我们更改值：
// Change the value of fred
dict.fred = "astra";
// The assignment creates and/or replaces key-value pairs
// Change the value of 2bob2
dict["2bob2"] = [1, 2, 3]; // Any legal value can be used
// Change value of our secret key
dict[key] = undefined;
// Contrary to popular beliefs, assigning "undefined" does not remove the key
// Go over all keys and values in our dictionary
for (key in dict) {
// A for-in loop goes over all properties, including inherited properties
// Let's use only our own properties
if (dict.hasOwnProperty(key)) {
console.log("key = " + key + ", value = " + dict[key]);
}
}
删除值也很容易：
// Let's delete fred
delete dict.fred;
// fred is removed, but the rest is still intact
// Let's delete 2bob2
delete dict["2bob2"];
// Let's delete our secret key
delete dict[key];
// Now dict is empty
// Let's replace it, recreating all original data
dict = {
fred: 42,
"2bob2": "twins!"
// We can't add the original secret key because it was dynamic, but
// we can only add static keys
// ...
// oh well
temp1: val
};
// Let's rename temp1 into our secret key:
if (key != "temp1") {
dict[key] = dict.temp1; // Copy the value
delete dict.temp1; // Kill the old key
} else {
// Do nothing; we are good ;-)
}
使用第一个示例。如果该键不存在，则会被添加。
var a = new Array();
a['name'] = 'oscar';
alert(a['name']);
弹出一个包含“oscar”的消息框。
尝试：
var text = 'name = oscar'
var dict = new Array()
var keyValuePair = text.replace(/ /g,'').split('=');
dict[ keyValuePair[0] ] = keyValuePair[1];
alert( dict[keyValuePair[0]] );
JavaScript 没有关联数组。它有对象。
以下代码都完全相同 - 将对象的'name'字段设置为'orion'。
var f = new Object(); f.name = 'orion';
var f = new Object(); f['name'] = 'orion';
var f = new Array(); f.name = 'orion';
var f = new Array(); f['name'] = 'orion';
var f = new XMLHttpRequest(); f['name'] = 'orion';
看起来你有一个关联数组，因为Array也是一个Object - 然而你实际上并没有向数组中添加任何东西；你是在对象上设置字段。
既然澄清了这一点，下面是针对你的示例的可行解决方案：
var text = '{ name = oscar }'
var dict = new Object();
// Remove {} and spaces
var cleaned = text.replace(/[{} ]/g, '');
// Split into key and value
var kvp = cleaned.split('=');
// Put in the object
dict[ kvp[0] ] = kvp[1];
alert( dict.name ); // Prints oscar.
var myArray = new Array();
myArray['one'] = 1;
myArray['two'] = 2;
myArray['three'] = 3;
// Show the values stored
for (var i in myArray) {
alert('key is: ' + i + ', value is: ' + myArray[i]);
}
原始代码（我添加了行号以便参考）：
1 var text = ' name = oscar '
2 var dict = new Array();
3 var keyValuePair = text.split(' = ');
4 dict[ keyValuePair[0] ] = 'whatever';
5 alert( dict ); // Prints nothing.
就快达成目标了...
line 1: you should do a trim on text so it is name = oscar.
line 3: okay as long as you always have spaces around your equal.
It might be better to not trim in line 1. Use = and trim each keyValuePair
add a line after 3 and before 4:
key = keyValuePair[0];`
line 4: Now becomes:
dict[key] = keyValuePair[1];
line 5: Change to:
alert( dict['name'] ); // It will print out 'oscar'
我想说的是 dict[keyValuePair[0]] 不起作用。你需要将一个字符串设置为 keyValuePair[0] 并将其用作关联键。这是我让它工作的唯一方法。设置完成后，您可以使用数字索引或带引号的键来引用它。
所有现代浏览器都支持 Map，这是一种键值对数据结构。以下原因使使用 Map 比 Object 更好：
- 对象具有原型，因此地图中有默认键。
- 对象的键是字符串，而在 Map 中可以是任何值。
- 您可以轻松获取 Map 的大小，而必须跟踪对象的大小。
示例：
var myMap = new Map();
var keyObj = {},
keyFunc = function () {},
keyString = "a string";
myMap.set(keyString, "value associated with 'a string'");
myMap.set(keyObj, "value associated with keyObj");
myMap.set(keyFunc, "value associated with keyFunc");
myMap.size; // 3
myMap.get(keyString); // "value associated with 'a string'"
myMap.get(keyObj); // "value associated with keyObj"
myMap.get(keyFunc); // "value associated with keyFunc"
var arr = [];
arr = {
key1: 'value1',
key2:'value2'
};
欲了解更多信息，请参阅以下链接：
var myArray = new Array();
myArray['one'] = 1;
myArray['two'] = 2;
myArray['three'] = 3;
// Show the values stored
for (var i in myArray) {
alert('key is: ' + i + ', value is: ' + myArray[i]);
}
这样做是可以的，但它会遍历数组对象的每个属性。
如果你只想遍历 myArray.one、myArray.two 等属性，可以尝试像这样：
myArray['one'] = 1;
myArray['two'] = 2;
myArray['three'] = 3;
myArray.push("one");
myArray.push("two");
myArray.push("three");
for(var i=0;i<maArray.length;i++){
console.log(myArray[myArray[i]])
}
Array和Object合并，并仅使用Object树！很棒的见解！通过使用Object.getOwnPropertyNames(obj/array)非常有用！ - Brian Cannardfor(i=0;i<maArray.length;i++{ - Peter Mortensenvar obj = {};
for (i = 0; i < data.length; i++) {
if(i%2==0) {
var left = data[i].substring(data[i].indexOf('.') + 1);
var right = data[i + 1].substring(data[i + 1].indexOf('.') + 1);
obj[left] = right;
count++;
}
}
console.log("obj");
console.log(obj);
// Show the values stored
for (var i in obj) {
console.log('key is: ' + i + ', value is: ' + obj[i]);
}
}
};
}
}）？ - Peter Mortensenconst arrayValues = [
"yPnPQpdVgzvSFdxRoyiwMxcx",
"yPnPQpdVgzvSFdxRoyiwMxcx",
"a96b3Z-rqt6U3QV_1032fxcsa",
"iNeoJfVnF7dXqARwnDOhj233dsd"
];
const newArr = arrayValues.map((x)=>{
return {
"_id":x
}
});
console.log(newArr)