Basically, you need to remove an element from the original array on every iteration and then get a random number with a max value equals to the size of filtered array.
Try this code (obviously it can be improved, eg copying original array ecc):
function removeItemOnce(arr, value) {
var index = arr.indexOf(value);
if (index > -1) {
arr.splice(index, 1);
}
return arr;
}
function newCustomer() {
showElement("customerPic");
for (var i = 0; i < 3; i++) {
let ix = randomNumber(0, toppings.length);
let v = toppings[ix];
toppings = removeItemOnce(toppings,v)
console.log("I would like " + v + " on my pizza, please");
}
}
More info about array item removing: https://stackoverflow.com/questions/5767325/how-can-i-remove-a-specific-item-from-an-array
Find the `index` of the array element you want to remove using [`indexOf`][2], and then remove that index with [`splice`][1].
> The splice() method changes the contents of an array by removing
> existing elements and/or adding new elements.
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-js -->
const array = [2, 5, 9];
console.log(array);
const index = array.indexOf(5);
if (index > -1) {
array.splice(index, 1);
}
// array = [2, 9]
console.log(array);
<!-- end snippet -->
The second parameter of `splice` is the number of elements to remove. Note that `splice` modifies the array in place and returns a new array containing the elements that have been removed.
___
For the reason of completeness, here are functions. The first function removes only a single occurrence (i.e. removing the first match of `5` from `[2,5,9,1,5,8,5]`), while the second function removes all occurrences:
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-js -->
function removeItemOnce(arr, value) {
var index = arr.indexOf(value);
if (index > -1) {
arr.splice(index, 1);
}
return arr;
}
function removeItemAll(arr, value) {
var i = 0;
while (i < arr.length) {
if (arr[i] === value) {
arr.splice(i, 1);
} else {
++i;
}
}
return arr;
}
// Usage
console.log(removeItemOnce([2,5,9,1,5,8,5], 5))
console.log(removeItemAll([2,5,9,1,5,8,5], 5))
<!-- end snippet -->
In TypeScript, these functions can stay type-safe with a type parameter:
```typescript
function removeItem<T>(arr: Array<T>, value: T): Array<T> {
const index = arr.indexOf(value);
if (index > -1) {
arr.splice(index, 1);
}
return arr;
}
```
[1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice
[2]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf
