Find unknown number in array of containing consecutive numbers javascript

Question

I have an array like this;

var specialOne = 3;
var array = [{value:"special"},{value:"1"},{value:"2"},{value:"specialOne"},{value:"4"},{value:"special"}];

And I need to convert it to this array;

var temp = [{value:"0"},{value:"1"},{value:"2"},{value:"3"},{value:"4"},{value:"5"}];

special's should be replaced with the appropriate value.

specialOne should be replaced with the given number.

How can i do this ?

More examples:

0,special,2,special,4,5 => 0,1,2,3,4,5
7,8,9,special => 7,8,9,10
special,special,10 => 8,9,10

I'm not sure what you want - too confusing. You can do this: for(var i=0; i<array.length; i++) array[i].value=""+i;, but I have a feeling that this is not what you mean/want... — iAmOren
– iAmOren, Commented Jul 21, 2020 at 11:40

Sven.hig · Accepted Answer · 2020-07-21 11:54:15Z

1

Maybe this is what you are after

var specialOne = 3;
var array1 = [{value:"special"},{value:"1"},{value:"2"},{value:"specialOne"},{value:"4"},{value:"special"}];
  function addspec(specialOne){
    array1.forEach((o,i)=>{
      if(o.value=="specialOne")o.value = specialOne.toString()   
      if(o.value=="special") o.value = array1[i-1]?(parseInt(array1[i-1].value)+1).toString():"0"
    })
  }
  addspec(3)
console.log(array1)

answered Jul 21, 2020 at 11:54

Sven.hig

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Comments

iAmOren · Accepted Answer · 2020-07-21 12:18:21Z

0

This may help you

var specialOne = 3;
var array = [
  { value: "special" },
  { value: "1" },
  { value: "2" },
  { value: "specialOne" },
  { value: "4" },
  { value: "special" }
];
for (i = 0; i < array.length; i++) {
  if (array[i].value == 'specialOne') {
    array[i].value = String(specialOne);
    console.log(array);
  } else if (array[i].value == 'special') {
    array[i].value = String(0);
    array.pop()
    array.push( { value: String(5) } );
  }
}

edited Jul 21, 2020 at 12:18

iAmOren

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answered Jul 21, 2020 at 12:00

Linux Torvalds

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Comments

Jerome · Accepted Answer · 2020-07-22 02:01:01Z

0

for (let i = 0; i < array.length; i++) {
   if (array[i].value === "special") array[i].value = i.toString();
   if (array[i].value === "specialOne") array[i].value = specialOne.toString();  
};

When you need to modify an array you should try to use a 'for' loop first. It is the most efficient as it will not modify the index of the array and will not return a new array (Imagine you have to 10 000 items to modify in your array... ).

Here it's very simple, you itere the array, if the condition match you modify the value (of the array itself).

edited Jul 22, 2020 at 2:01

answered Jul 21, 2020 at 12:03

Jerome

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1 Comment

Aplet123 Over a year ago

Please try to elaborate a bit more on why this code works.

Mr_Green · Accepted Answer · 2020-07-22 07:50:05Z

0

Something like this?

var specialOne = 3;
var array = [{
  value: "special"
}, {
  value: "1"
}, {
  value: "2"
}, {
  value: "specialOne"
}, {
  value: "4"
}, {
  value: "special"
}];

function getValues(array) {
  let counterSync = 0;
  let backCheck = [];
  let inFlow = false;
  let backCheckOnce = false;
  return array.map((m, i) => {
    if (isNaN(parseInt(m.value))) {
      if (inFlow || window[m.value]) {
        m.value = "" + (window[m.value] || (counterSync + 1));
      } else {
        if (i === 0) {
          backCheckOnce = true;
        }
        backCheck.push(m);
      }
    } else {
      inFlow = true;
      // do reverse check only once
      if (backCheckOnce) {
        backCheck.reverse().forEach((x, idx) => x.value = "" + (+m.value - 1));
        backCheckOnce = false;
      }

    }
    counterSync = +m.value;
    return m;
  });
}

console.log(getValues(array));

edited Jul 22, 2020 at 7:50

answered Jul 21, 2020 at 12:11

Mr_Green

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3 Comments

Yavuz Selim Özmen Over a year ago

No, If start with 5, must be example : 5,6,special,8 => 5,6,7,8

Mr_Green Over a year ago

@YavuzSelimÖzmen Updated. The only issue I see is the object should always start with number instead of special or specialOne.

Mr_Green Over a year ago

@YavuzSelimÖzmen Hey I fixed the first value as special also. Do understand the code before using it (it can be refactored)

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