use*_*623 50 javascript arrays filter
我想简化一个对象数组.我们假设我有以下数组:
var users = [{
name: 'John',
email: 'johnson@mail.com',
age: 25,
address: 'USA'
},
{
name: 'Tom',
email: 'tom@mail.com',
age: 35,
address: 'England'
},
{
name: 'Mark',
email: 'mark@mail.com',
age: 28,
address: 'England'
}];
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并过滤对象:
var filter = {address: 'England', name: 'Mark'};
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例如,我需要按地址和名称过滤所有用户,所以我循环过滤器对象属性并检查出来:
function filterUsers (users, filter) {
var result = [];
for (var prop in filter) {
if (filter.hasOwnProperty(prop)) {
//at the first iteration prop will be address
for (var i = 0; i < filter.length; i++) {
if (users[i][prop] === filter[prop]) {
result.push(users[i]);
}
}
}
}
return result;
}
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因此,第一次迭代期间,当prop - address
将等于'England'
两个用户将被添加到阵列结果(与名汤和Mark),但在第二次迭代时,prop name
就等于Mark
只在最后一个用户应添加到阵列的结果,但我出现了两个数组中的元素.
我有一个小小的想法,为什么它发生但仍然坚持它,无法找到一个很好的解决方案来解决它.任何帮助都很明显.谢谢.
Rag*_*dra 70
你可以这样做
var filter = {
address: 'England',
name: 'Mark'
};
var users = [{
name: 'John',
email: 'johnson@mail.com',
age: 25,
address: 'USA'
},
{
name: 'Tom',
email: 'tom@mail.com',
age: 35,
address: 'England'
},
{
name: 'Mark',
email: 'mark@mail.com',
age: 28,
address: 'England'
}
];
users= users.filter(function(item) {
for (var key in filter) {
if (item[key] === undefined || item[key] != filter[key])
return false;
}
return true;
});
console.log(users)
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SoE*_*zPz 18
对于那些喜欢简洁代码的人来说,另一种看法.
注意:FILTER方法可以使用额外的这个参数,然后使用E6箭头函数,我们可以重复使用正确的这个来获得一个漂亮的单行.
var users = [{name: 'John',email: 'johnson@mail.com',age: 25,address: 'USA'},
{name: 'Tom',email: 'tom@mail.com',age: 35,address: 'England'},
{name: 'Mark',email: 'mark@mail.com',age: 28,address: 'England'}];
var query = {address: "England", name: "Mark"};
var result = users.filter(search, query);
function search(user){
return Object.keys(this).every((key) => user[key] === this[key]);
}
// |----------------------- Code for displaying results -----------------|
var element = document.getElementById('result');
function createMarkUp(data){
Object.keys(query).forEach(function(key){
var p = document.createElement('p');
p.appendChild(document.createTextNode(
key.toUpperCase() + ': ' + result[0][key]));
element.appendChild(p);
});
}
createMarkUp(result);
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<div id="result"></div>
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小智 18
users.filter(o => o.address == 'England' && o.name == 'Mark')
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对于 es6 来说好多了。或者你可以使用 || (或)这样的运算符
users.filter(o => {return (o.address == 'England' || o.name == 'Mark')})
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cyb*_*age 13
你可以排成一行
users = users.filter(obj => obj.name == filter.name && obj.address == filter.address)
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pms*_*ani 10
改进这里的好答案,以下是我的解决方案:
const rawData = [
{ name: 'John', email: 'johnson@mail.com', age: 25, address: 'USA' },
{ name: 'Tom', email: 'tom@mail.com', age: 35, address: 'England' },
{ name: 'Mark', email: 'mark@mail.com', age: 28, address: 'England' }
]
const filters = { address: 'England', age: 28 }
const filteredData = rawData.filter(i =>
Object.entries(filters).every(([k, v]) => i[k] === v)
)
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使用Array.Filter()和箭头函数,我们可以使用
users = users.filter(x => x.name == 'Mark' && x.address == 'England');
这是完整的片段
// initializing list of users
var users = [{
name: 'John',
email: 'johnson@mail.com',
age: 25,
address: 'USA'
},
{
name: 'Tom',
email: 'tom@mail.com',
age: 35,
address: 'England'
},
{
name: 'Mark',
email: 'mark@mail.com',
age: 28,
address: 'England'
}
];
//filtering the users array and saving
//result back in users variable
users = users.filter(x => x.name == 'Mark' && x.address == 'England');
//logging out the result in console
console.log(users);
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过滤掉性别 = 'm' 的人
var people = [
{
name: 'john',
age: 10,
gender: 'm'
},
{
name: 'joseph',
age: 12,
gender: 'm'
},
{
name: 'annie',
age: 8,
gender: 'f'
}
]
var filters = {
gender: 'm'
}
var out = people.filter(person => {
return Object.keys(filters).every(filter => {
return filters[filter] === person[filter]
});
})
console.log(out)
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过滤掉性别 = 'm' 且姓名 = 'joseph' 的人
var people = [
{
name: 'john',
age: 10,
gender: 'm'
},
{
name: 'joseph',
age: 12,
gender: 'm'
},
{
name: 'annie',
age: 8,
gender: 'f'
}
]
var filters = {
gender: 'm',
name: 'joseph'
}
var out = people.filter(person => {
return Object.keys(filters).every(filter => {
return filters[filter] === person[filter]
});
})
console.log(out)
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您可以根据需要提供任意多个过滤器。
我认为这可能会有所帮助。
const filters = ['a', 'b'];
const results = [
{
name: 'Result 1',
category: ['a']
},
{
name: 'Result 2',
category: ['a', 'b']
},
{
name: 'Result 3',
category: ['c', 'a', 'b', 'd']
}
];
const filteredResults = results.filter(item =>
filters.every(val => item.category.indexOf(val) > -1)
);
console.log(filteredResults);
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也可以这样做:
this.users = this.users.filter((item) => {
return (item.name.toString().toLowerCase().indexOf(val.toLowerCase()) > -1 ||
item.address.toLowerCase().indexOf(val.toLowerCase()) > -1 ||
item.age.toLowerCase().indexOf(val.toLowerCase()) > -1 ||
item.email.toLowerCase().indexOf(val.toLowerCase()) > -1);
})
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这是在过滤器中使用箭头功能的ES6版本。之所以将其发布为答案是因为我们大多数人现在都在使用ES6,这可能会帮助读者使用箭头功能let和const以高级方式进行过滤。
const filter = {
address: 'England',
name: 'Mark'
};
let users = [{
name: 'John',
email: 'johnson@mail.com',
age: 25,
address: 'USA'
},
{
name: 'Tom',
email: 'tom@mail.com',
age: 35,
address: 'England'
},
{
name: 'Mark',
email: 'mark@mail.com',
age: 28,
address: 'England'
}
];
users= users.filter(item => {
for (let key in filter) {
if (item[key] === undefined || item[key] != filter[key])
return false;
}
return true;
});
console.log(users)
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