debugger

debugger 的宣告會執行可用的除錯功能，例如設定斷點。如果沒有可用的除錯功能，這個宣告沒有任何作用。

語法

debugger;

以下示例示範了插入 debugger 宣告的程式碼，它會在函式被呼叫、而且有除錯器的時候執行除錯器。

function potentiallyBuggyCode() {
    debugger;
    // 執行並驗證一些潛在的問題、或是單步執行之類的。
}

呼叫除錯器時，程式會在 debugger 宣告處暫停執行。它有點像是程式碼的斷點。

規範	狀態	註解
ECMAScript Latest Draft (ECMA-262) The definition of 'Debugger statement' in that specification.	Draft
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Debugger statement' in that specification.	Standard
ECMAScript 5.1 (ECMA-262) The definition of 'Debugger statement' in that specification.	Standard	初期定義
ECMAScript 3rd Edition (ECMA-262) The definition of 'Debugger statement' in that specification.	Standard
ECMAScript 1st Edition (ECMA-262) The definition of 'Debugger statement' in that specification.	Standard	只作為保留字而提到

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`debugger`	Chrome Full support Yes	Edge Full support Yes	Firefox Full support 1	IE Full support Yes	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support 4	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes	nodejs Full support Yes