window in js code example

Example 1: js find all custom window properties

Object.keys(window).filter(x => typeof(window[x]) !== 'function' &&
  Object.entries(
    Object.getOwnPropertyDescriptor(window, x)).filter(e =>
      ['value', 'writable', 'enumerable', 'configurable'].includes(e[0]) && e[1]
    ).length === 4)

Example 2: how to query in windows js

function getQueryStringValue (key) {  
  return decodeURIComponent(window.location.search.replace(new RegExp("^(?:.*[&\\?]" + encodeURIComponent(key).replace(/[\.\+\*]/g, "\\$&") + "(?:\\=([^&]*))?)?.*$", "i"), "$1"));  
}  

// Would write the value of the QueryString-variable called name to the console  
console.log(getQueryStringValue("name"));