linq-js-docs/src/resources/zh-cn/apis/IEnumerable/methods/defaultIfEmpty.json

use linq and lamdba in javascript

{
    "histroys": [
        {
            "since": "2.1.15",
            "overloads": [
                {
                    "parameters": [
                        {
                            "name": "defaultValue",
                            "types": [
                                "any"
                            ],
                            "descriptions": [
                                "序列为空时要返回的序列所包含的值"
                            ]
                        }
                    ],
                    "returns": {
                        "type": "IEnumerable",
                        "descriptions": [
                            "如果源序列为空, 返回包含单一 defaultValue 元素的新序列, 否则返回源序列"
                        ]
                    },
                    "description": "如果源序列为空, 返回包含单一元素的新序列, 否则返回源序列",
                    "remarks": [
                        "此方法通过延迟执行的方式实现",
                        "此方法可以用于与 groupJoin 方法结合使用, 生成一个左外部联接"
                    ],
                    "sees": [
                        {
                            "apis": "IEnumerable",
                            "method": "groupJoin"
                        },
                        {
                            "href": "https://msdn.microsoft.com/{language}/library/bb355419(v=vs.110).aspx",
                            "title": "Microsoft MSDN"
                        }
                    ]
                }
            ]
        }
    ]
}