Question 297131 in Javascript Question posted in
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How can I create a 2d array out of a normal array through splitting each element (in javascript)

I have got a very large string, it contains about 13000 times different data of the same kind. I have now created a function to split this string into an array of 13000 elements. Now each element of those 13000 still consists out of different data seperated with spaces (it looks something like: 20.8967489 50.29868 3 9867 86983648
How can I create a 2 dimensional array storing 5 elements for each of the 13000 elements?

I have tried something like this:

function getValuableData(){
    const fullData = [[]];
        text.replace('   ','  ');
        text.replace('  ',' ');
        const data = text.split('a')
    data.forEach(element => {
        const singleData = element.split(' ')
        fullData.concat(singleData)
    });
    }
Tags:

3

Answers


  1. 0

    I’d map this array and split each element:

    const result = 
    text.split(/s*as*/)          // First split
        .map(x => x.split(/s+/)); // Second split
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  2. 0

    Let see how we can get a 2 dimensional array storing 5 elements for each using single for loop

    • update your getValuableData function
    function getValuableData(){
       text.replace('   ','  ');
       text.replace('  ',' ');
       return text.split('a');
 }
    • convert above split result to 2 dimensional array with single loop
    function get2Dimensional() {
        const oneDimArray = getValuableData();
        const rows = [];
        const itemsPerRow = 5;

        for (let i = 0; i < oneDimArray.length; i += itemsPerRow) {
            const row = oneDimArray.slice(i, i + itemsPerRow);
            rows.push(row);
        }

        return rows;
  }
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  3. 0

    If you have spaces around your split character you can use String::indexOf() to navigate by spaces in a big string, faster than splitting by a regex:

    ` Chrome/119
---------------------------------------------------
Alexander   1.00x  |  x100  123  224  233  240  256
Mureinik    2.08x  |  x100  256  264  270  275  282
---------------------------------------------------
https://github.com/silentmantra/benchmark `

    const str = '20.8967489 50.29868 3 9867 86983648';

let longStr = '';
let count = 13000;
while(count--) longStr += (longStr ? ' a ' : '') + str;

//@benchmark Mureinik
longStr.split(/s*as*/)          // First split
        .map(x => x.split(/s+/));


//@benchmark Alexander

const result = [];
let chunk = [], prev = 0, next;
while((next = longStr.indexOf(' ', prev)) > 0){
  chunk.push(longStr.slice(prev, prev = next));
  prev++;
  if(longStr[prev] === 'a'){
    result.push(chunk);
    chunk = [];
    prev+=2;
  }
}

result.push(chunk);
result;

/*@end*/eval(atob('e2xldCBlPWRvY3VtZW50LmJvZHkucXVlcnlTZWxlY3Rvcigic2NyaXB0Iik7aWYoIWUubWF0Y2hlcygiW2JlbmNobWFya10iKSl7bGV0IHQ9ZG9jdW1lbnQuY3JlYXRlRWxlbWVudCgic2NyaXB0Iik7dC5zcmM9Imh0dHBzOi8vY2RuLmpzZGVsaXZyLm5ldC9naC9zaWxlbnRtYW50cmEvYmVuY2htYXJrL2xvYWRlci5qcyIsdC5kZWZlcj0hMCxkb2N1bWVudC5oZWFkLmFwcGVuZENoaWxkKHQpfX0='));
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