如何从对象数组中提取对象(数组)?

How do I extract an object(array) from an array of objects?

假设我有以下数据集:

const art = {
    'fields': [
        {title:'Title 1'}, 
        {'text': [
            {spaces: '1'}, {link: 'This is a link'}, {mouse: 'Yes'}
        ]}, 
        {title: 'Title 2'}, 
        {title:'Title 3'},
        {'text': [
            {spaces: '2'}, {link: 'This is a different link'}, {mouse: 'No'}
        ]},
    ]};

我想从 "spaces" 属性 中提取一个新对象(数组)。除此之外,我需要识别那些没有 "spaces" 属性 的 "title" 对象与空值相关联。

我想以这样的方式结束:

newArray = ['', '1', '', '', '2']

这可能吗?如果我的术语不是很好,请原谅我。新手。

你可以这样做

const newArr = art.fields.map(space => {
  return {...space.text}
});

所以我假设您想 return 一个包含文本数组对象的新数组

应该不会太难。尝试 Javascript 的 map() 函数...

const art = {
    'fields': [
        {title:'Title 1'}, 
        {'text': [
            {spaces: '1'}, {link: 'This is a link'}, {mouse: 'Yes'}
        ]}, 
        {title: 'Title 2'}, 
        {title:'Title 3'},
        {'text': [
            {spaces: '2'}, {link: 'This is a different link'}, {mouse: 'No'}
        ]},
    ]};

const spaces = art.fields.map(function(field) {
  if(field.text) {
    return field.text[0].spaces;
  }
  return '';
});

console.log("Spaces?");

console.log(spaces);

结果...

"Spaces?"
["", "1", "", "", "2"]

查看 JSBIN. Map returns a function's result for an iteration over an array. Check out the Mozilla Developer Network Docs 上的代码。

您可以使用 map 方法为 art.fields 数组中的每一项计算一个值。

const art = {
    'fields': [
        {title:'Title 1'}, 
        {'text': [
            {spaces: '1'}, {link: 'This is a link'}, {mouse: 'Yes'}
        ]}, 
        {title: 'Title 2'}, 
        {title:'Title 3'},
        {'text': [
            {spaces: '2'}, {link: 'This is a different link'}, {mouse: 'No'}
        ]},
    ]};

var newArray = art.fields.map(function(o){
  return 'text' in o ? o.text[0].spaces : '';
});

console.log(newArray);

如果您的文本数组将有多个空格,那么它应该遍历它并添加空格值,如下所示:

const art = {
  'fields': [{
      title: 'Title 1'
    },
    {
      'text': [{
        spaces: '1'
      }, {
        link: 'This is a link'
      }, {
        mouse: 'Yes'
      }]
    },
    {
      title: 'Title 2'
    },
    {
      title: 'Title 3'
    },
    {
      'text': [{
        spaces: '2'
      }, {
        link: 'This is a different link'
      }, {
        mouse: 'No'
      }]
    },
  ]
};


var res = art.fields.reduce((ini, curr, idx) => {
  if (curr.text) {
    curr.text.forEach(arr => {
      arr.spaces && ini.push(arr.spaces);
    });
  } else {
    ini.push('');
  }
  return ini;
}, [])
console.log(res);