比较JavaScript对象数组并设置特定值，适用于从主数组源添加和删除的情况

我们可以使用循环和一些内置函数来比较两个对象数组并设置特定值，以处理添加和删除操作。下面是一个示例代码：

let mainArray = [ { id: 1, name: 'John', age: 20 }, { id: 2, name: 'Jane', age: 25 }, { id: 3, name: 'Bob', age: 30 } ];

let updatedArray = [ { id: 1, name: 'John Doe', age: 21 }, { id: 2, name: 'Jane', age: 25 }, { id: 4, name: 'Alice', age: 35 } ];

//处理添加项目 const addedItems = updatedArray.filter(item => !mainArray.find(itm => itm.id === item.id)); addedItems.forEach(item => item.created = true);

//处理删除项目 const deletedItems = mainArray.filter(item => !updatedArray.find(itm => itm.id === item.id)); deletedItems.forEach(item => item.deleted = true);

//更新或添加项目 updatedArray.forEach(item => { const mainItem = mainArray.find(itm => itm.id === item.id); if (mainItem) { //如果找到匹配项，则更新值 Object.keys(item).forEach(key => { mainItem[key] = item[key]; }); } else { //如果没有找到匹配项，则添加新项目 item.added = true; mainArray.push(item); } });

console.log(mainArray); // [{ id: 1, name: 'John Doe', age: 21 }, { id: 2, name: 'Jane', age: 25 }, { id: 3, name: 'Bob', age: 30 }, { id: 4, name: 'Alice', age: 35, added: true }] console.log(addedItems); // [{ id: 4, name: 'Alice', age: 35, added: true }] console.log(deletedItems); // [{ id: 3, name: 'Bob', age: 30, deleted: true }]