所以该程序正在尝试分配一个教室。到目前为止，程序已询问用户班级代码、学生人数以及是否需要计算机，并已使用字段“cRObj.name”、“cRObj.students”和 cRObj.computers 构建了一个数组（因此教室名称将列在 cRObj.name 下，学生人数将列在 cRObj.students 下，以及是否有计算机（是/否）列在 cRObj.computers 下。
我必须搜索对象数组，以尝试找到与用户输入的学生数量相匹配的条目（我想我知道该怎么做）。
但是，之后它需要检查 cRObj.computers 是否等于用户的输入，然后如果前两个匹配，则将条目保存在 cRObj.name 下，我不确定该怎么做。
您可以使用数组.过滤器 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter，这需要一个函数，该函数传递数组的每个项目并返回 true 或 false，并返回一个新数组，该数组仅包含传递给 filter 的函数将返回 true 的项目。
您可以部分应用柯里化函数。柯里化函数示例：
const plus = a => b => a+b;
const plusTen = plus(10);//is a function that takes number b and adds 10 (a is 10)
const eleven = plusTen(1); takes 1 for value of b and 10 for value of a
以下是如何使用柯里化函数进行比较：
const equal = search => value =>
search === value;
const isFive = equal(5);
//... this will return false, search is 5 and value is 10
// 5===10 is false
if(isFive(10)){
提供一个将从对象获取属性的函数：
const getA = o => (o&&o.a);
getA({a:10};//will return 10
getA({hasNoA:10};//will return undefined
组合所有以创建过滤器函数：
const data = [
{a:3,b:2},
{a:4,b:6},
{a:5,b:8},
{a:6,b:9},
{a:7,b:3}
];
//filer function needs a getter (like getA)
// comparer that is a partially applied function that takes a value and compares it
// with o.something (if getter is getA it'll compare with o.a)
// o is the object that needs to be filtered (like elements of data: data[0]={a:3,b:2})
const filterFn = getter => comparer => o =>
comparer(getter(o));
//get a property
const getA = o => (o&&o.a);
//you can write getB I'm sure
// compare search === value
const equal = search => value =>
search === value;
// compare search <= value
const biggerEqual = search => value =>
search <= value;
// all data items where item.a === 5
console.log(
"a is 5",
data.filter(
filterFn(getA)(equal(5))//partially apply equal with search of 5
)
);
//all data items where item.a >= 5
console.log(
"a equals or bigger 5",
data.filter(
filterFn(getA)(biggerEqual(5))//partially apply biggerEqual with search of 5
)
);
//if you want to compare b with some things you could do
// const getB = o => (o&&o.b);
// data
// .filter(filterFn(getA)(biggerEqual(5)))//a bigger or equal 5
// .filter(filterFn(getB)(can you guess?)//b equal 5
// here is an example that takes an array of data and an array of filter functions
// it'll apply filter on array of data for every function
const filterData = (array, filterFunctions) =>
filterFunctions.reduce(
(result,filterFunction)=>result.filter(filterFunction),
array
);
// using filterData
console.log(
"using filterData",
filterData(data,[
filterFn(getA)(biggerEqual(5))//partially apply biggerEqual with search of 5
//,you could add more filters here
])
)
对于更复杂的比较器（例如想知道对象的值是否在值列表中），您可以执行以下操作：
const filterFn = getter => comparer => o =>
comparer(getter(o));
const data= [{id:23},{id:11},{id:435}];
const values= [23, 435, 5];
const getId = o => o.id;
const isIn = haystack => needle => haystack.includes(needle);
const isInValues = isIn(values);
console.log(
data.filter(filterFn(getId)(isInValues))
)
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