Question

var data1 = [
    {"year":2000,"country":"Madagascar","country_id":847,"group":"Economic Statistics "},
    {"year":2005,"country":"Madagascar","country_id":847,"group":"Economic Statistics "},
    {"year":2000,"country":"Madagascar","country_id":847,"group":"Economic Statistics "},
    {"year":2005,"country":"Libya","country_id":846,"group":"Demographic  and Social Statistics "},
    {"year":2008,"country":"Libya","country_id":846,"group":"Demographic  and Social Statistics "},
    {"year":2005,"country":"Libya","country_id":846,"group":"Demographic  and Social Statistics "}
]

这是我的JSON数据，我希望根据国家/地区进行过滤，使用underscore.js年份（唯一）

Answer 1

如果要根据某个键选择唯一元素，可以使用_.uniq（或_.unique）方法。它可选地进行回调以将元素转换为其键以进行比较。具有相同内容的数组比较不同，因此您可能需要对您的ke进行字符串化; JSON.stringify可以用于此（或者您可以使用+ - 带来后果）：

data1=_.uniq(data1, function(x){
    return JSON.stringify([x.year, x.country_id])
});

演示：http://jsfiddle.net/honnza/xGr9e/

如果您只想保留year和country_id的某些特定值的值，则更容易：

data1=_.filter(data1, function(x){
    return x.year === target_year && x.country_id === target_country_id
});

使用underdescore.js过滤

1 个答案: