Question

javascript

1.Write a function delay that accepts two arguments, a callback and the wait time in milliseconds. Delay should return a function that, when invoked waits for the specified amount of time before executing. HINT - research setTimeout();

2.Create a function saveOutput that accepts a function (that will accept one argument), and a string (that will act as a password). saveOutput will then return a function that behaves exactly like the passed-in function, except for when the password string is passed in as an argument. When this happens, the returned function will return an object with all previously passed-in arguments as keys, and the corresponding outputs as values.

3.Create a function dateStamp that accepts a function and returns a function. The returned function will accept whatever arguments the passed-in function accepts and return an object with a date key whose value is today's date (not including the time) represented as a human-readable string (see the Date object for conversion methods), and an output key that contains the result from invoking the passed-in function.

4.Create a function defineFirstArg that accepts a function and an argument. Also, the function being passed in will accept at least one argument. defineFirstArg will return a new function that invokes the passed-in function with the passed-in argument as the passed-in function's first argument. Additional arguments needed by the passed-in function will need to be passed into the returned function.

Answer 1

Q1)

function delay(func, wait, ...rest) {

function rundelay() {

func(...rest);

}

setTimeout(rundelay, wait);

}

Q2)

const saveOutput = (inputFunc, str) => {

let newOb = {};

return function (value) {

if (value === str){

return newOb;

}

else {

newOb[value] = inputFunc(value);

return inputFunc(value)

}

}

}

const valuedouble = function(n) { return n * 2; };

const valuedoubleAndLog = saveOutput(valuedouble, 'boo');

console.log(valuedoubleAndLog(2));

console.log(valuedoubleAndLog(9));

console.log(valuedoubleAndLog('boo'));

Q3)

const dateStamp = (inputFunc) =>

{

let today = new Date();

return (...args) =>

{

return {

date: today.toDateString(),

output: inputFunc(...args)

}

}

}

const stampdouble = dateStamp(n => n * 2);

console.log(stampdouble(4));

console.log(stampdouble(6));

const stampMax = dateStamp((x, y) => Math.max(x, y));

console.log(stampMax(-5, 6));

console.log(stampMax(1, 4));

Q4)

const defineFirstArg = (inputFunc, arg) => {

return function (...addtionalArgs) {

return inputFunc(arg, ...addtionalArgs)

}

}

f2 = defineFirstArg(console.log,"b")

f2("a","d",'c')