在 javascript 中的 function 参数中调用 function 的算法

Question

here is my code problem, There are three arguments in my function x, y and num . num must be multiplied with x and y and return.

 function abc(num, x, y) { return num * x + " " + num * y; } console.log( abc(5, 2, 4) //returns 10 20 ); console.log( abc(5, abc(5, 6, 6), 4) //doesn't return 30 30 20 ) function abc1(num, x, y) { if (isNaN(x)) { return x + " " + y * num; //now it returns 30 30 20 for abc(5,abc(5,6,6),4) } return num * x + " " + num * y; } console.log( abc1(5, 2, 4) //returns 10 20 ); console.log( abc1(5, abc(5, 6, 6), 4) //now it returns 30 30 20 for abc(5,abc(5,6,6),4) )

I also want to know how to achieve if I call the function below (function inside the argument of the same function)-

abc(5,abc(abc(5,abc(5,6,6),abc(5,abc(5,6,6),4)))) // it must return something like how abc(5,abc(5,6,6),4) should return 30 30 20

I want when I call the function abc(5,2,abc(5,abc(5,4,4),3)) should return all parameters(except num ) every time like 10 20 20 15 for calling the function - abc(5,2,abc(5,abc(5,4,4),3)) if I place the same function in the function Parameter/arguments.

I tried but when I call the function inside the same function arguments like abc(5,abc(5,6,6),4) the x in the function abc(num,x,y) becomes NaN hence returns like NaN 20 but not 30 30 20 .

but how to do for this abc(5,abc(abc(5,abc(5,6,6),abc(5,abc(5,6,6),4)))) to return the same way like above.

Any online source would help, Thanks.

Answer 1

You could return an array and check if the value is an array and use the values instead of multiplying with the given factor.

 function fn(f, a, b) { return [...(Array.isArray(a)? a: [f * a]), ...(Array.isArray(b)? b: [f * b]), ]; } console.log(...fn(5, 6, 6)); // [30, 30] console.log(...fn(5, fn(5, 6, 6), 4)); // [30, 30, 20] console.log(...fn(5, 2, fn(5, fn(5, 4, 4), 3))); // [10, 20, 20, 15]

An even shorter approach

 function fn(f, ...values) { return values.flatMap(x => Array.isArray(x)? x: [f * x]); } console.log(...fn(5, 6, 6)); // [30, 30] console.log(...fn(5, fn(5, 6, 6), 4)); // [30, 30, 20] console.log(...fn(5, 2, fn(5, fn(5, 4, 4), 3))); // [10, 20, 20, 15]