代码报错 需要找下原因 // 初始化 const start = document.getElementById("getstart").addEventListener("click", function () { let select_bu01 = 0; select_bu02 = 0; select_bu03 = 0; select_bu04 = 0; select_bu05 = 0; select_y01 = 0 select_y02 = 0 select_y03 = 0 select_y04 = 0 select_y05 = 0 select_y06 = 0 select_y07 = 0 select_y08 = 0 select_y09 = 0 select_y10 = 0 select_h01 = 0 select_h02 = 0 ifMDM = 0 let tmp_data = { MDM: ifMDM, BU01: select_bu01, BU02: select_bu02, BU03: select_bu03, BU04: select_bu04, BU05: select_bu05, Year1: select_y01, Year2: select_y02, Year3: select_y03, Year4: select_y04, Year5: select_y05, Year6: select_y06, Year7: select_y07, Year8: select_y08, Year9: select_y09, Year10: select_y10 }; let jsonString = JSON.stringify(tmp_data); console.log(jsonString); return jsonString; });

这段代码中的问题在于，你在点击事件的处理函数中使用了 `return` 语句来返回 `jsonString`。然而，`addEventListener` 方法并不期望处理函数返回值，所以无法正确处理这个返回值。

如果你想在点击事件处理函数执行完毕后获取 `jsonString` 的值，可以考虑将其保存到外部变量或者调用另一个函数来处理。

下面是修改后的代码示例：

const start = document.getElementById("getstart").addEventListener("click", function () {
    let select_bu01 = 0;
    let select_bu02 = 0;
    let select_bu03 = 0;
    let select_bu04 = 0;
    let select_bu05 = 0;
    let select_y01 = 0;
    let select_y02 = 0;
    let select_y03 = 0;
    let select_y04 = 0;
    let select_y05 = 0;
    let select_y06 = 0;
    let select_y07 = 0;
    let select_y08 = 0;
    let select_y09 = 0;
    let select_y10 = 0;
    let select_h01 = 0;
    let select_h02 = 0;
    let ifMDM = 0;

    let tmp_data = {
        MDM: ifMDM,
        BU01: select_bu01,
        BU02: select_bu02,
        BU03: select_bu03,
        BU04: select_bu04,
        BU05: select_bu05,
        Year1: select_y01,
        Year2: select_y02,
        Year3: select_y03,
        Year4: select_y04,
        Year5: select_y05,
        Year6: select_y06,
        Year7: select_y07,
        Year8: select_y08,
        Year9: select_y09,
        Year10: select_y10
    };

    let jsonString = JSON.stringify(tmp_data);
    console.log(jsonString);

    // 在这里可以使用 jsonString 或者调用其他函数来处理它
});

在上述示例中，我移除了 `return` 语句，并将 `jsonString` 的值保留在了点击事件处理函数的内部。你可以在 `console.log` 后面的注释处使用 `jsonString` 或者调用其他函数来处理它。