我尝试通过以下命令更新

npm uninstall -g angular-cli @angular/cli
npm cache clean
npm install -g @angular/cli@latest

在我尝试运行任何ng命令后成功安装

ng version 
ng help

我收到了这个错误

ng help
/usr/local/lib/node_modules/@angular/cli/models/config/config.js:15
    constructor(_configPath,schema,configJson,fallbacks = []) {
                                                           ^

SyntaxError: Unexpected token =
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:374:25)
    at Object.Module._extensions..js (module.js:417:10)
    at Module.load (module.js:344:32)
    at Function.Module._load (module.js:301:12)
    at Module.require (module.js:354:17)
    at require (internal/module.js:12:17)
    at Object.<anonymous> (/usr/local/lib/node_modules/@angular/cli/models/config.js:2:18)
    at Module._compile (module.js:410:26)
    at Object.Module._extensions..js (module.js:417:10)