如何在*ngfor[重复]中显示数组的对象数组

Question

我有一个这样的数组

 tdata = {
    jam: [1, 2, 4, 5],
    ram: [11, 12, 34, 14],
    sam: [21, 22, 23, 24],
    jug: ["a", "b", "c", "d"],
    tam: [31, 32, 33, 34]
  };

我想打印/显示对象键，如jam，ram，sam作为表格标题，其值在各自的表格中与Pprimeng表格成角度。我尝试了各种方法，但无法正确显示。动态值的Primeng表

<p-table [columns]="cols" [value]="products">
    <ng-template pTemplate="header" let-columns>
        <tr>
            <th *ngFor="let col of columns">
                {{col.header}}
            </th>
        </tr>
    </ng-template>
    <ng-template pTemplate="body" let-rowData let-columns="columns">
        <tr>
            <td *ngFor="let col of columns">
                {{rowData[col.field]}}
            </td>
        </tr>
    </ng-template>
</p-table>

如果我想显示，我需要数组在表单中自动显示

tdata = [
        {jam:1,ram:11,sam:21,jug:"a",tam:31},
        {jam:2,ram:12,sam:22,jug:"b",tam:32},
        {jam:3,ram:34,sam:23,jug:"c",tam:33},
        {jam:5,ram:14,sam:24,jug:"d",tam:34 }
      ]

tdata中的值可能会动态更改，它们也来自后端和密钥

Answer 1

您可以使用keyvaluepipe。

<div *ngFor="let item of tdata | keyvalue">
  {{ item.key }}
</div>

Answer 2

首先获取数组的长度。然后迭代Object.keys以获取每个键的值以获取新行。

tdata = {
    jam: [1, 2, 4, 5],
    ram: [11, 12, 34, 14],
    sam: [21, 22, 23, 24],
    jug: ["a", "b", "c", "d"],
    tam: [31, 32, 33, 34]
};

let tdataFormatted = [];
let rowLength = Object.keys(tdata)[0].length; //get the length of the first property.

let i = 0;
while (i < rowLength) {

    let newObj = {};

    for (key in tdata) {
        newObj[key] = tdata[key][i];
    }

    tdataFormatted.push(newObj)

    i++;
}

console.log(tdataFormatted);