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_.pick
根据第二个参数的key的数组，筛选第一个参数中的值并返回
var object = { 'a': 1, 'b': '2', 'c': 3 };
_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }
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_.pickBy
根据第二个参数条件，筛选出符合条件的值
var object = { 'a': 1, 'b': '2', 'c': 3 };
_.pickBy(object, _.isNumber);
// => { 'a': 1, 'c': 3 }
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_.omit
根据第二个参数，筛选第一个参数中独有的元素
var object = { 'a': 1, 'b': '2', 'c': 3 };
_.omit(object, ['a', 'c']); // => { 'b': '2' }
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_.omitBy
根据第二个参数条件，筛选出不符合第二个参数条件的元素
var object = { 'a': 1, 'b': '2', 'c': 3 };
_.omitBy(object, _.isNumber);
// => { 'b': '2' }
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_.reject
根据条件去除某个元素。
var foo = [
{id: 0, name: "aaa", age: 33},
{id: 1, name: "bbb", age: 25}
]
var bar = _.reject(foo, ['id', 0])
//bar = [{id: 1, name: "bbb", age: 25}]
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_.keys
返回object中的所有key
_.key() _.keyBy
以某个属性为键，将数组转为对象
var foo = [
{id: 0, name: "aaa", age: 33},
{id: 1, name: "bbb", age: 25}
]
var bar = _.keyBy(foo, 'name')
//bar = {
// aaa: {id: 0, name: "aaa", age: 33},
// bbb: {id: 1, name: "bbb", age: 25}
//}
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_.cloneDeep
深拷贝
var bar = _.cloneDeep(foo)
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_.find
查找数组
var foo = [
{id: 0, name: "aaa", age: 33},
{id: 1, name: "bbb", age: 25}
]
var bar = _.find(foo, ['id', 0])
//bar = {id: 0, name: "aaa", age: 33}
注意一下如果没找到的话，会返回undefined，要处理一下
-
_.filter
根据条件过滤出符合条件的元素，返回新数组
var foo = [
{id: 0, name: "aaa", age: 33},
{id: 1, name: "bbb", age: 25}
]
var bar = _.filter(foo, ['name', "aaa"])
//bar = {
// aaa: {id: 0, name: "aaa", age: 33}
//}
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_.map
从集合中挑出一个key，将其值作为数组返回
var foo = [
{id: 0, name: "aaa", age: 33},
{id: 1, name: "bbb", age: 25}
]
var bar = _.map(foo, 'name')
//bar = ["aaa", "bbb"]
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_.max _.min _.sum
数组中最大值、最小值、数组求和
var foo = [1, 2, 3, 4]
var bar = _.max(foo)
//bar = 4
bar = _.min(foo)
//bar = 1
bar = _.sum(foo)
//bar = 10
-
_.pad _.padStart _.padEnd
在两端、开头、末尾补齐字符
var foo = "helloworld"
var bar = _.pad(foo, 14, '-')
//bar = --helloworld--
bar = _.padStart(foo, 14, '-')
//bar = ----helloworld
bar = _.padEnd(foo, 14, '-')
//bar = helloworld----
选出json数组中id最大的一项
var foo = [
{id: 0, name: "aaa", age: 33},
{id: 1, name: "bbb", age: 25}
]
var bar = _.find(foo, ['id', _.max(_.map(foo, 'id'))])
// bar = {id: 1, name: "bbb", age: 25}
