/**
* 判斷是否為null
*
* Unit Test: {@link https://github.com/yuda-lyu/wsemi/blob/master/test/isnull.test.mjs Github}
* @memberOf wsemi
* @param {*} v 輸入任意資料
* @returns {Boolean} 回傳判斷布林值
* @example
*
* console.log(isnull(null))
* // => true
*
*/
function isnull(v) {
let c = Object.prototype.toString.call(v)
return c === '[object Null]'
}
export default isnull