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how to check if value exists from value? [closed]

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if I have the following values
0 - a
1 - b
2 - c
4 - d
8 - e
16 - f
if i get the value 17, how would i know that values b and f are in that values, some for the others as these can be mixed together by adding, so bd value would be 6

Convert your value to binary format. For example 17 => 10001. Then select only 1's. You can make for loop starts from 'a' to 'z'. Increase characters +1 then convert to character.
This is sample code:
function foo(num) {
if (num == 0)
return 'a';
const binaryNum = (num >>> 0).toString(2);
function nextChar(c) {
return String.fromCharCode(c.charCodeAt(0) + 1);
}
var converted = '';
var asci = 'b';
for(var i=binaryNum.length-1; i>=0; --i) {
if (binaryNum.charAt(i) == '1')
converted+=asci;
asci = nextChar(asci);
}
return converted;
}
console.log(foo(17));
console.log(foo(0));
console.log(foo(6));
console.log(foo(28));
Output is:
bf
a
bd
def
Note that 'bd' is 5.

Much like the bank note problem, reduce down the value in denominations, then pick out the index for the map to the letter.
const v1 = [0, 1, 2, 4, 8, 16];
const v2 = ['a', 'b', 'c', 'd', 'e', 'f'];
let value = 7
const vMap = new Map();
for (let i = v1.length - 1; i >= 0 && value; i--) {
const qty = Math.floor(value / v1[i]);
qty && vMap.set(v1[i], qty);
value = value % v1[i];
}
const entries = Array.from(vMap.entries());
console.log(entries.map(([curr, qty]) => `${curr} * ${qty} = ${curr * qty} is ${v2[v1.indexOf(curr)]}`))

Want to Sort with Loop In JS [closed]

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let fruits = [mango,banana,avocado,apple,orange,lychee];
let prices = [50,90,65,300,600,900]; // not constant value;
//Solution with If else
if(prices > 0 && prices <= 50) console.log("Mango#0-50")
if(prices > 51 && prices <= 65)console.log("Mango#0-50<br>Banana#51-65")
//So on
Is there any way to short it with loop?
This is how the result should look like
Mango#0-50
Banana#51-65
avocado#65-90
apple#91-300
orange#301-600
lychee#601-900
rest#>901
Note: I do not want to use If else;

let i = 1
fruits.map(fruit => `${fruit.name}#${i}-${i+=100}`);

You could map the fruits with their price range and slice the array by the wanted length and return a joined string.
function getValues(price) {
return temp
.slice(0, (prices.findIndex(p => price <= p) + 1) || prices.length + 1)
.join('<br>');
}
const
fruits = ['mango', 'banana', 'avocado', 'apple', 'orange', 'lychee'],
prices = [50, 90, 65, 300, 600, 900].sort((a, b) => a - b),
temp = [...fruits.map((f, i, { length }) => `${f}#${prices[i - 1] + 1 || 0}-${prices[i]}`), `rest#>${prices[prices.length - 1] + 1}`];
console.log(getValues(100));
console.log(getValues(300));
console.log(getValues(301));
console.log(getValues(1000));

Create random number different from the numbers inside an array [closed]

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I have an array for example [2,8,5,6], and I want to generate a random number different from the numbers that are inside the array, and that this number is not greater than 100.
Many thanks friends

Using Set to avoid collisions
arr = [2, 8, 5, 6]
getRandom = (exclude, min = 0, max = 100) => {
let rand = Math.random() * 100 | 0
while (exclude.has(rand)) rand = min + Math.random() * max | 0
exclude.add(rand)
return rand
}
arr = new Set(arr)
console.log(getRandom(arr))
console.log(getRandom(arr))
console.log(getRandom(arr))
console.log(getRandom(arr))
console.log([...arr])

You could generate an array of the numbers up to the max that you want, then remove the ones that you don't want, and the pick a random element from the resulting array, for example:
const max = 100
const exclude = [2,8,5,6]
const randomIdx = Math.floor(Math.random() * (max + 1 - exclude.length))
const randomNum = [...Array(max + 1).keys()].filter(k => !exclude.includes(k))[randomIdx]
console.log(randomNum)

Angular / JS generate random Uniq Serial ID [closed]

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I'm creating a function that generate a random Uniq Serial id by replacing a string with this format ; xxxx-xxxx-xxxx-xxxx , the goal is to get a serial like that : ABCD-1234-EFGH-5678 ,the first and third parts are a letters and the second and last parts are numbers, this is my code :
public generateUniqSerial() {
return 'xxxx-xxxx-xxx-xxxx'.replace(/[x]/g, function (c) {
let r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8)
return v.toString(16)
})
}
it give a result like that : "7f8f-0d9a-fd5-450f"
, how to edit this function to get a result with this format : ABCD-1234-EFGH-6789 ?

You can do something like this to generate a random Uniq Serial id with a format like ABCD-1234-EFGH-5678:
function rnd(t) {
let str = '';
const min = t === 'a' ? 10 : 0;
const max = t === 'n' ? 10 : 62;
for (let i = 0; i++ < 4;) {
let r = Math.random() * (max - min) + min << 0;
str += String.fromCharCode(r += r > 9 ? r < 36 ? 55 : 61 : 48);
}
return str;
}
function generateUniqSerial() {
return `${rnd('a')}-${rnd('n')}-${rnd('a')}-${rnd('n')}`
}
console.log(generateUniqSerial())
console.log(generateUniqSerial())

When I'm asked to do things like this I like to start with a "string of letters" and a "string of digits." My logic then simply consists of choosing a random index into the appropriate source string to get each character that I need. I like to do it this way because to me it's "extremely obvious" what I am doing and equally easy to desk-check that it will work.

how to find the sum of all integers present in a string which is divisible by 3? [closed]

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Find the sum of all the numbers in a string which is divisible by 3 and also find the last such number (Use JavaScript). Example “The best 6 of 8 will get 9 points”, sum = 15, last=9.

Sure - use split, reduce and filter with % (modulo) for divisibility:
const str = "The best 6 of 8 will get 9 points";
const strArr = str.split("");
const threesArr = strArr.filter(e => parseInt(e) % 3 == 0);
const sumOfThrees = threesArr.reduce((acc, curr) => acc + parseInt(curr), 0);
const allNumbers = strArr.filter(e => parseInt(e));
const lastNumber = allNumbers[allNumbers.length - 1];
console.log("Sum: " + sumOfThrees);
console.log("Last: " + lastNumber);