Angular *ngFor嵌套循环[重复]

Question

我有一个带有这样的对象数组的 json

questions = [
        {
            question: "What is your name?",
            options: [
                {
                    option1 : "Abc",                    
                }, {
                    option2 : "Def"
                }, {
                    option3 : "Ghi"
                }, {
                    option4 : "Jkl"
                }
            ]
        },
        {
            question: "Where is your Home Town?",
            options: [
                {
                    option1: "Abc"
                }, {
                    option2: "Def"
                }, {
                    option3: "Ghi"
                }, {
                    option4: "Jkl" 
                }
            ]
        }
      ]

在我看来，我想像这样用 ngFor 渲染那个 json

你叫什么名字？

• Abc
• 默认
• 吉
• Jkl

Answer 1

questions = [{
            question: "What is your name?",
            options: [ "Abc", "Def", "Ghi", "Jkl"] 
           }, {            {
            question: "Where is your Home Town?",
            options: [ "Abc", "Def", "Ghi", "Jkl"] 
              }]

<div *ngFor="let q of questions">
    <span> {{q.question}}</span>
    <ul>
      <li *ngFor="option in q.options">{{option}} </li>
   </ul>
</div>

你应该使用如上修改你的 json 格式

Answer 2

创建一个这样的管道

import { PipeTransform, Pipe } from '@angular/core';

@Pipe({name: 'keys'})
export class KeysPipe implements PipeTransform {
  transform(value, args:string[]) : any {
    let keys = [];
    for (let key in value) {
      keys.push(key);
    }
    return keys;
  }
}

这样调用管道

<div *ngFor="#q of questions">
    <span> {{q.question}}</span>
    <ul>
      <li *ngFor="#option of q.options  ">
        <span *ngFor="#key of option | keys ">{{key}} : {{option[key]}}  </span>
      </li>
   </ul>
</div>