如何在嵌套的 object 中從 javascript 中的父 object 獲取值？

Question

我正在使用材質 ui 框架並使用createMuiTheme創建主題，如何在嵌套的 object 中使用父 object 值。 （我知道我可以在函數上方定義全局變量）；
為了更好地理解它，請閱讀以下代碼：

import {createMuiTheme} from "@material-ui/core";
import {grey, blueGrey, teal, red} from "@material-ui/core/colors";

export default createMuiTheme({

    palette: {
        common: {
            mainColor: blueGrey[500],
            headerColor: blueGrey[700],
            white: grey[50],
            black: grey[900],
        },
        primary: {
            main: palette.common.mainColor,  /* <= how to I can do this in Javascript */
        },
        secondary: {
            main: grey[300]
        },
        text: {
            primary: palette.common.white, /* <= or this */
            secondary: grey[500]
        },

    }

})

謝謝。

Answer 1

你不能。 但是你可以這樣做。

import {createMuiTheme} from "@material-ui/core";
import {grey, blueGrey, teal, red} from "@material-ui/core/colors";

const theme = {
  palette: {
    common: {
        mainColor: blueGrey[500],
        headerColor: blueGrey[700],
        white: grey[50],
        black: grey[900],
    },
    secondary: {
        main: grey[300]
    },
}

export default createMuiTheme({
  ...theme,
  palette: {
    ...theme.pallete,
    primary: {
        main: theme.palette.common.mainColor,  /* <= how to I can do this in Javascript */
    },
   text: {
        primary: theme.palette.common.white, /* <= or this */
        secondary: grey[500]
    }
  }
})