我有一个javascript对象,它看起来像
dict1 = {"key1":"value1",
"key2":"value2",
"key3":"value3",
"key4":"value4",
"key5":"value5"}
接下来我有一个数组,它是 arr1 = ["key1","key2"]
我需要做的就是从数组中基于dict1的元素中获取值,并将它们连接成字符串。听起来相当简单。
dict1[arr1[0]] + '-' + dict1[arr1[1]]
输出:
value1-value2
对我来说,棘手的部分是数组中的 arr1 可以是任何长度,但总是dict1中存在的键的子集。例如
arr1= ["key2","key5"]
arr1= ["key1","key5","key3"]
arr1= ["key4"]
基于这些输入,我们希望得到以下输出
value2-value5
value1-value5-value3
value4
我在写一个动态创建字符串的通用脚本时遇到了麻烦。
你可以映射到你想从对象中 "摘取 "值的键,并将所有这些值用以下方法连接起来 join
.
const dict1 = {
"key1": "value1",
"key2": "value2",
"key3": "value3",
"key4": "value4",
"key5": "value5"
}
arr1 = ["key2", "key5"];
arr2 = ["key1", "key5", "key3"];
arr3 = ["key4"];
const pluckAndConcat = (obj, keys) => keys.map(key => obj[key]).join("-");
console.log(pluckAndConcat(dict1, arr1));
console.log(pluckAndConcat(dict1, arr2));
console.log(pluckAndConcat(dict1, arr3));
你可以使用函数reduce如下。
let dict1 = {"key1":"value1","key2":"value2", "key3":"value3", "key4":"value4", "key5":"value5"};
let buildString = function(arr, obj) {
return arr.reduce((a, s) => a.concat(obj[s]), []).join("-")
};
console.log(buildString(["key2","key5"], dict1));
console.log(buildString(["key1","key5","key3"], dict1));
console.log(buildString(["key4"], dict1));
很简单.
你所需要做的就是每次取一个键,然后从你的 dict
然后将其添加到你的主字符串中。
假设。
let dict1 = {
"key1":"value1",
"key2":"value2",
"key3":"value3",
"key4":"value4",
"key5":"value5"
}
你可以用reduce或者map
reduce
的方式。
let genString = (subArray, obj) => subArray.reduce((acc, v, i) => [...acc, obj[v]] ,[]).join('-')
map
way:
let genString = (subArray, obj) => subArray.map((v, i) => obj[v]).join('-')
你可以用这样的方式。
genString(["key1","key5","key3"], dict1)