How to fix my function trying to find min value in javascript

You could use arguments, an array like object of the function.

function findvalue() {
    var i = 0,
        min = arguments[0];

    for (i = 1; i < arguments.length; i++) {
        if (min > arguments[i]) {
            min = arguments[i];
        }
    }
    return min;
}
console.log(findvalue(11, 12, 13, 21, 22, 23, 97, 98, 99));

A shorter approach could be the use of rest parameters ... and spread syntax ... for the values for Math.min.

function findvalue(...args) {
    return Math.min(...args)
}
console.log(findvalue(11, 12, 13, 21, 22, 23, 97, 98, 99));

Your function definition is incorrect, as well as how you are calling your function.

You are looking to iterate over an array, but you are calling your function with a bunch of numbers as the arguments. You instead need 1 parameter (argument) to call your function, which should be an array .

You have to instead call it this way:

findvalue([11, 12, 13, 21, 22, 23, 97, 98, 99])

Your function definition needs to be:

function findvalue(array) {
  var i = 0;
  var min = array[0];
  for (i = 1; i < array.length; i++) {
    if (min > array[i]) {
      min = array[i];
    }
  }
  return min;
}

As noted in the comments, you could modify your function definition to retain your initial way of calling the function. This is done by using rest parameters

The MDN docs describe rest parameters as:

The rest parameter syntax allows us to represent an indefinite number of arguments as an array.

Call the function as you did: findvalue(11, 12, 13, 21, 22, 23, 97, 98, 99)

Your function definition would be:

function findvalue(...array) {
      var i = 0;
      var min = array[0];
      for (i = 1; i < array.length; i++) {
        if (min > array[i]) {
          min = array[i];
        }
      }
      return min;
    }

You can use Math.min

function findMin() {
   // arguments is an Array-like object corresponding to the arguments passed to a function. 
   return Math.min.apply(Math, arguments)
}

console.log(findMin(2,4,1,0,9,-2));

The missing thing in your function is the array must be a parameter of your function.

As you wrote it, the function is always trying to find the minimum in an empty array.

It is currently completely ignoring the example values you passed when you called your function.

So, instead of writing var array = [] in the body of you function, you have several possibilities :

1st possibility : take the array as parameter : declare your function as function(array) and change your call to actually pass an array of values : findValues([11, 12, 13, 21 ...]), and remove the var array = [] inside the body of your function.

2nd possiblity (my favorite): just replace var array = [] by var array = [...arguments]

Documention on the arguments object here : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments

(and also, please note that let is now best practice than var)

See Nina 's answer for full snippets examples with arguments

try like this

function findvalue() {
	var order = Array.from(arguments).sort(function(a,b){ return a - b; });
	var min = order[0];
	//var max = order[order.length-1];
	return min;
}
// MIN value
console.log(findvalue(23, 97, 98, 99, 11, 12, 13, 21, 22));

I am sure the Arrow function will simplify your work.

    //Variable diclaration
    var numbers = [11, 12, 13, 21, 22, 23, 97, 98, 99];

    //Arrow Function to find Min Number
    var minfinder = numbers.reduce((a, b) => Math.min(a, b));

    //Consloe Output
    console.log("Min Number is: " + minfinder);