js题集24
1.实现MagicFunction
MagicFunction(3) == 3; // should return true
MagicFunction(1, 2) == 3; // should return true
MagicFunction(1, 3)(2) == 6; // should return true
MagicFunction(1, 2)(3, 4, 5)(6)(7, 10) == 38; // should return true *1+2+3+4+5+6+7+10=38;
2.实现如下结果
seven(times(five())); // must return 35
four(plus(nine())); // must return 13
eight(minus(three())); // must return 5
six(dividedBy(two())); // must return 3
//your code........补充下面代码
function zero() {}
function one() {}
function two() {}
function three() {}
function four() {}
function five() {}
function six() {}
function seven() {}
function eight() {}
function nine() {}
function plus() {}
function minus() {}
function times() {}
function dividedBy() {}
3.实现lazy函数
new Lazy()
.add(filterNumbers)
.add(filterRange, 2, 7)
.add(max)
.invoke([1, 8, 6, [], "7", -1, {v: 5}, 4]); //6
//你可能需要下列函数用来测试结果
function max() {
return Math.max.apply(null, arguments);
}
function filterNumbers() {
return Array.prototype.filter.call(arguments, function(value) {
return isNumeric(value);
});
}
function isNumeric(n) {
return !isNaN(n) && Number(n) === n;
}
function filterRange(min, max) {
var args = Array.prototype.slice.call(arguments, 2);
return Array.prototype.filter.call(args, function(value) {
return min <= value && value <= max;
});
}
4.实现--自己猜
function func1(arg1, arg2) { ... }
var map = createArgumentMap(func1,'valueOfArg1', 'valueOfArg2');
console.log(map['arg1']); // writes 'valueOfArg1'
console.log(map['arg2']); // writes 'valueOfArg2'
5.实现extend
extend( {a: 1, b: 2}, {c: 3} ) // should === {a: 1, b: 2, c: 3}
extend( {a: 1, b: 2}, {c: 3}, {d: 4} ) // should === {a: 1, b: 2, c: 3, d: 4}
extend( {a: 1, b: 2}, {a: 3, c: 3} ) // should === {a: 1, b: 2, c: 3}
extend( {a: false, b: null}, {a: true, b: 2, c: 3} ) // should === {a: false, b: null, c: 3}
。。。。。。。。
//补充:原出题者情况说明较少 笔者补充一个arguments的情况过滤掉非object
//NODE 下 可以直接用isObject函数进行 非node下
//参考如下:
//
function isObject(val) {
if (val === null) { return false;}
return ( (typeof val === 'function') || (typeof val === 'object') );
}
1)arguments=
{
'0': { a: 1, b: 2, length: 6 },
'1': [],
'2': 'nope',
'3': false,
'4': [Function],
'5': { c: 3, a: 3 }
}// 要过滤掉1,2,3,4