CODEWITHSUNDEEP
javascript
S.Rafiq
S.Rafiq

Reputation: 63

How to stop repeating ifs

const idx = query.idx; 
    let page = 1;

    if (idx > 19){
        page = 2
    };

    if (idx > 39){
        page = 3
    };

    if (idx > 59){
        page = 4
    };

    console.log(page);

This is my code I am trying to change the page variable after every 19, 39, 59 etc is there a better way to write this code as if i have more indexes i will need to add more ifs

Upvotes: 2

Views: 97

Answers (3)

Jax297
Jax297

Reputation: 657

This should be a solution

 const idx = query.idx; 
    let page = Math.floor(idx / 20) + 1;
    console.log(page);

if you need to use only ifs:

if (idx > 19 && idx < 40){
    page = 2
};

if (idx > 39 && idx < 60){
    page = 3
};

if (idx > 59){
    page = 4
};

Upvotes: 0

dfsq
dfsq

Reputation: 193261

Divide by 20 (page size) and round result. Something like this:

const idx = query.idx; 
const page = Math.ceil((idx + 1) / 20)

console.log(page);

Couple of tests:

[
  1,
  5,
  15,
  19,
  20,
  21,
  36,
  39,
  40,
  41,
  49,
  59,
  60,
  68,
].forEach(idx => {
  console.log(idx, Math.ceil((idx + 1) / 20))
})

Upvotes: 5

GibboK
GibboK

Reputation: 73908

Try the following

const findPage = (idx, limit)=> Math.ceil(idx / limit)+1

console.log(findPage(19, 20))
console.log(findPage(39, 20))
console.log(findPage(59, 20))

Upvotes: 0

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