如何在多维数组中返回 boolean 之后的值？

Question

我试图过滤多维数组以仅返回此数组中 boolean 之后的索引。

该数组中的第一个键需要像“Tafeblad model”和“Uitstraling”一样留在数组中，以及布尔值后面的可选值

["Tafelblad model", true, "Rechthoekig", "Vierkant", "Ovaal / Rond / Overig"],
["Uitstraling", "Licht robuust", "Midden robuust", true, "Zwaar robuust", "Weinig", "Midden (standaard)", true, "Veel oneffenheden en scheuren"]`

新数组就像

["Tafelblad model", "Rechthoekig"],
["Uitstraling", "Zwaar robuust", "Veel oneffenheden en scheuren"]`

Answer 1

您可以关闭您设置的标志以保留您看到的下一个条目：

let flag = true; // We want the first one
const newArray = array.filter(entry => {
    const keep = flag;
    flag = typeof entry === "boolean";
    return keep;
});

现场示例：

 function example(array) { let flag = true; // We want the first one const newArray = array.filter(entry => { const keep = flag; flag = typeof entry === "boolean"; return keep; }); console.log(newArray); } example(["Tafelblad model", true, "Rechthoekig", "Vierkant", "Ovaal / Rond / Overig"]); example(["Uitstraling", "Licht robuust", "Midden robuust", true, "Zwaar robuust", "Weinig", "Midden (standaard)", true, "Veel oneffenheden en scheuren"]);

Answer 2

您可以为此使用.filter(..) function，这是一个示例：

 let arr1 = ["Tafelblad model", true, "Rechthoekig", "Vierkant", "Ovaal / Rond / Overig"]; let arr2 = ["Uitstraling", "Licht robuust", "Midden robuust", true, "Zwaar robuust", "Weinig", "Midden (standaard)", true, "Veel oneffenheden en scheuren"]; const filterFn = (value, index, arr) => { return index === 0 || arr[index - 1] === true; }; arr1 = arr1.filter(filterFn); arr2 = arr2.filter(filterFn); console.log(arr1); console.log(arr2);

传递给.filter(..)的回调 function 接收当前迭代的值、当前迭代的索引和原始数组作为参数。 filterFn function 中的条件检查迭代的索引是否为0 （该值是数组中的第一个值）或前一项严格等于true

Answer 3

使用map()和filter()

 let arrays = [ ["Tafelblad model", true, "Rechthoekig", "Vierkant", "Ovaal / Rond / Overig"], ["Uitstraling", "Licht robuust", "Midden robuust", true, "Zwaar robuust", "Weinig", "Midden (standaard)", true, "Veel oneffenheden en scheuren"] ] let result = arrays.map(arr => { return arr.filter((v, i) => typeof arr[i - 1] === "boolean" || i == 0); }) console.log(result)