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[英]How to add numerical values together from keys with the same name in one object?
[英]How to $.extend 2 objects by adding numerical values together from keys with the same name?
我目前有2個obj並使用jquery擴展函數,但是它會覆蓋具有相同名稱的鍵的值。 如何將值一起添加?
var obj1 = {
"orange": 2,
"apple": 1,
"grape": 1
};
var obj2 = {
"orange": 5,
"apple": 1,
"banana": 1
};
mergedObj = $.extend({}, obj1, obj2);
var printObj = typeof JSON != "undefined" ? JSON.stringify : function (obj) {
var arr = [];
$.each(obj, function (key, val) {
var next = key + ": ";
next += $.isPlainObject(val) ? printObj(val) : val;
arr.push(next);
});
return "{ " + arr.join(", ") + " }";
};
console.log('all together: ' + printObj(mergedObj));
我得到obj1 = {"orange":5,"apple":1, "grape":1, "banana":1}
我需要的是obj1 = {"orange":7,"apple":2, "grape":1, "banana":1}
所有$.extend
都會加入這兩個對象但它不會添加值,它會覆蓋它們。 您將不得不手動執行此操作。 $.extend
對於添加或修改對象的水果很有用,但如果你需要總和,你將需要循環:
var obj1 = { orange: 2, apple: 1, grape: 1 };
var obj2 = { orange: 5, apple: 1, banana: 1 };
var result = $.extend({}, obj1, obj2);
for (var o in result) {
result[o] = (obj1[o] || 0) + (obj2[o] || 0);
}
console.log(result); //=> { orange: 7, apple: 2, grape: 1, banana: 1 }
這不是.extend()
工作原理; 你必須實現自己的:
function mergeObjects() {
var mergedObj = arguments[0] || {};
for (var i = 1; i < arguments.length; i++) {
var obj = arguments[i];
for (var key in obj) {
if( obj.hasOwnProperty(key) ) {
if( mergedObj[key] ) {
mergedObj[key] += obj[key];
}
else {
mergedObj[key] = obj[key];
}
}
}
}
return mergedObj;
}
用法:
var obj1 = { "orange": 2, "apple": 1, "grape": 1 };
var obj2 = { "orange": 5, "apple": 1, "banana": 1 };
var mergedObj = mergeObjects( obj1, obj2);
// mergedObj {"orange":7,"apple":2,"grape":1,"banana":1}
當然,就像.extend()
,這將適用於任意數量的對象 - 而不僅僅是2。
以下是您可以使用的一些代碼:
obj1 = {"orange":2,"apple":1, "grape":1};
obj2 = {"orange":5,"apple":1, "banana":1};
var joined = {};
// add numbers in arr to joined
function addItems(arr) {
// cycle through the keys in the array
for (var x in arr) {
// get the existing value or create it as zero, then add the new value
joined[x] = (joined[x] || 0) + arr[x];
}
}
addItems(obj1);
addItems(obj2);
console.log(JSON.stringify(joined));
輸出:
{ “橙色”:7, “蘋果”:2, “葡萄”:1, “香蕉”:1}
沒有花哨的東西,只是簡單的Javascript:
c[k] || 0
如果c[k]
沒有值,則為c[k] || 0
,它變為零。
var a = {orange:2, apple:1, grape:1};
var b = {orange:5, apple:1, banana:1};
var c = {};
var k;
for (k in a) {c[k] = 0 + a[k] + (c[k] || 0)}
for (k in b) {c[k] = 0 + b[k] + (c[k] || 0)}
window.alert(JSON.stringify(c));
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