函數調用後的兩組括號 - Two sets of parentheses after function call

問題：

I was looking how filters works in Angularjs and I saw that we need to send 2 sets of parentheses.我正在研究過濾器在 Angularjs 中的工作原理，我發現我們需要發送 2 組括號。

$filter('number')(number[, fractionSize])

What does it means and how do we handle it with JavaScript?它是什麼意思，我們如何用 JavaScript 處理它？

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解決方案：

參考一： https://en.stackoom.com/question/1EVch
參考二： https://stackoom.com/question/1EVch