数组和对象如何可变，字符串，数字和所有原始数据类型如何不可变？

Question

数组和对象如何可变，但字符串，数字和所有原始数据类型是不可变的？

{"status":201,"statusText":"Created","responseText":"","responseHeaders":{"connection":"Keep-Alive","content-language":"en-US","content-length":"0","date":"Fri, 17 May 2019 05:42:45 GMT","keep-alive":"timeout=5, max=100","location":"/mfp/api/registration/clients/1e746550-e804-4ee7-88ba-b99896qqqqpwo","server":"Apache/2.4.39 (Win64) OpenSSL/1.1.1b","via":"1.1 ","x-powered-by":"Servlet/3.0"},"errorMsg":"Created","errorCode":"201"}

这是一成不变的吗？