声明前使用的变量

此警告类别由 qmllint 拼写[var-used-before-declaration] 。

此处在变量声明之前使用了变量

发生了什么？

您在声明之前使用了变量。

为什么这样做不好？

这会增加代码的阅读难度。用let 或const 声明的变量会在运行时出错。

示例

import QtQuick

Item {
    function f() {
        x = 42; // x is used before its declaration
        let x;
    }

    Component.onCompleted: f()
}

要修复此警告，请将声明移到使用之前：

import QtQuick

Item {
    function f() {
        let x;
        x = 42;
    }

    Component.onCompleted: f()
}

另请参阅 QML 文档中的 JavaScript 表达式。

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