create arrays based on elements of odd and even indexes of another array

Question

I want to fill two arrays (sentences and links ) with odd and even indexes of sentence array :

Here is what I tried with no success:

     let link_sentence = ">60-1> don't you worry >6-2> I gonna make sure that >16-32> tomorrow is another great day"; // 
                 
        let sentence =  link_sentence.split(">")
        let sentences= []
        let links = []
        for(let i = 0; i < sentence.length; i += 2) {  
        
            sentences.push(sentence[i]);
        }
        console.log(sentences)

The expected output should be :

//let links = ["60-1", "6-2", "16-32"];
//let sentences = ["don't you worry", "I gonna make sure that", "tommorow is  another great day"];

sentences looks awfully close to being correct, and you haven't even tried to compute links. — Scott Hunter
– Scott Hunter, Commented Aug 6, 2019 at 19:05
I have no idea of how links should be computed and yes if sentences don't look awfully close to being correct I would never ask for help — Sara Ree
– Sara Ree, Commented Aug 6, 2019 at 19:07

connexo · Accepted Answer · 2019-08-06 19:33:06Z

4

You could match the parts and omit empty string with splitting.

var link_sentence = ">60-1> don't you worry >6-2> I gonna make sure that >16-32> tomorrow is another great day",
    sentences = [],
    links = [];

link_sentence
    .match(/\>[^>]+/g)
    .reduce(
        (r, s, i) => (r[i % 2].push(s.slice(1)), r),
        [links, sentences]
    );

console.log(sentences);
console.log(links);

.as-console-wrapper { max-height: 100% !important; top: 0; }

edited Aug 6, 2019 at 19:33

connexo

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answered Aug 6, 2019 at 19:13

Nina Scholz

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1 Comment

Icepickle Over a year ago

Lets give people a headache :) But nicely done as always, Nina ^_^

JamesT · Accepted Answer · 2019-08-06 19:15:31Z

2

Your initial attempt is close and if you modify your for loop slightly you can achieve the result you want.

// remove first value from the array if the value is empty
if (!sentence[0]) {
    sentence.shift();
}

for(let i = 0; i < sentence.length; i++) {  
    if (i % 2 === 0) {
        links.push(sentence[i]);
    } else {
        sentences.push(sentence[i]);
    }
}

edited Aug 6, 2019 at 19:15

answered Aug 6, 2019 at 19:07

JamesT

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2 Comments

Icepickle Over a year ago

except that the sentence starts with a > therefor the first link would be empty, then a link, then a sentence, so your index would be incorrect :)

Icepickle Over a year ago

I think it's fine, as it seems that the OP understands the logic behind it :) The only downside might be that the links & sentences would be "disconnected"

connexo · Accepted Answer · 2019-08-06 19:22:43Z

2

Here's a simple solution using Array.prototype.reduce:

const sentence = ">60-1> don't you worry >6-2> I gonna make sure that >16-32> tomorrow is another great day".split(">")

const {links, sentences} = sentence.reduce((acc, val, index) => {
  acc[index % 2 === 0 ? 'links' : 'sentences'].push(val);
  return acc;
}, {
  links: [],
  sentences: []
});

console.log(links, sentences);

edited Aug 6, 2019 at 19:22

answered Aug 6, 2019 at 19:14

connexo

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Comments

alenk · Accepted Answer · 2019-08-06 19:13:06Z

1

You can do it like this:

const link_sentence = ">60-1> don't you worry >6-2> I gonna make sure that >16-32> tomorrow is another great day"
const sentence =  link_sentence.split(">")
const sentences = []
const links = []

sentence.forEach((el, idx) => {
  if (idx % 2 === 0) {
    // if even
    sentences.push(el)
  } else {
    // if odd
    links.push(el)
  }
})

answered Aug 6, 2019 at 19:13

alenk

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Comments

Christian Carrillo · Accepted Answer · 2019-08-06 19:21:42Z

1

You could use:

let link_sentence = ">60-1> don't you worry >6-2> I gonna make sure that >16-32> tomorrow is another great day"; // 
                 
let sentence =  link_sentence.split(">")
let sentences = []
let links = []

// removing the first element of array: [""]
sentence.splice(0, 1)

// iterating sentence
sentence.forEach((item, index) => {
  // if the index is even push to links, else push to sentences
  if (index % 2 === 0) {
    links.push(item)
  } else {
    // trim white spaces
    sentences.push(item.trim())
  }
})
console.log(links)
console.log(sentences)

answered Aug 6, 2019 at 19:21

Christian Carrillo

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