Javascript - Iterate through an object and count all strings containing specific text within each and all arrays

TheFall1976
August 2, 2023
257 views
1 vote
2 Answers

I have an object containing arrays, I want to count the number of occurrences a particular string is found across all arrays in the object.

const festivals = {
  'Danny': ['Glastonbury','Glastonbury','Leeds','Leeds','Leeds','Benicassim','MadCool'],
  'Jimbo': ['Glastonbury','Glastonbury','Leeds','Leeds','Leeds','Leeds','Benicassim','MadCool'],
  'Richard': ['Glastonbury','Leeds','Leeds','Benicassim','MadCool'],
  'John': ['Glastonbury','Leeds']
}

 let totalFestivals = 0
 let target = 'Benicassim'

for (let festival in festivals){
  if (festivals[festival] === target){
    totalFestivals++
  }
}
console.log (totalFestivals). //

Answers

- arielkoo
- August 2, 2023 at 2:18 am
- 0 votes
0
maybe something like that?…
```
for (let festival in festivals) {
  const festivalArray = festivals[festival];
  for (let i = 0; i < festivalArray.length; i++) {
    if (festivalArray[i] === target) {
      totalFestivals++;
    }
  }
}
```
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- Meniev
- August 2, 2023 at 2:23 am
- 0 votes
0
First, the == is not working because you are telling javascript this:

Example with Danny:
```
    if(['Glastonbury','Glastonbury','Leeds','Leeds','Leeds','Benicassim','MadCool'] == 'Benicassim'){
        ...
    }
```
Instead you do this:
```
festivals[festival].includes(target)
```
Details:

The includes function return true if the parameter is inside a list.

Problem:

But because of the way you write the function, your result will be max 4, because you have 4 list and your function and the includes do not count the occurrences.

Solution:

With the second for in the code below you will compare every index of the current list(example : ‘Danny’ list) with target and if they are equal the totalFestivals increase.
```
for (let festival in festivals){
    for(var i = 0; i < festivals[festival].length; i++){
        if (festivals[festival][i] === target){
            totalFestivals++
        }
    }
}
```
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