Struggling to sort through an array in JavaScript and looking for some guidance

Here is the array I'm working with in JavaScript:

let myArray = ["Bob", "Katy", "Bob", "Bob", "Katy"];

I am looking to filter this array by checking if the current value matches the value before or after it. I am a bit unsure on how to approach this, can someone provide guidance?

Currently, I am familiar with using the .filter() method to filter an array based on a specified condition, but I am uncertain about comparing a value with its neighboring values.

Here's what I have so far:

 let numberOfBobs = myArray.filter(x => x === "Bob");

However, this does not meet my requirements. I want to count 'Bob' only if there is another 'Bob' immediately before or after it in the array.

javascriptarraysmethodsfilter

Answer №1

Your specific scenario is a bit unclear to me, but if you're aiming to retrieve an array like ['Bob', 'Bob'] based on the given example (which corresponds to the last occurrences of 'Bob' when applying your filter to ['Bob', 'Katy', 'Bob', 'Bob']), you could utilize the index parameter in the filter callback function. Here's an example:

const filteredArray = myArray.filter((item, index) => {
  // Handle special cases such as first and last elements
  return item === myArray[index - 1] || item === myArray[index + 1];
})

In this code snippet, the element will be included in the output array if it matches either the previous or next item.

Answer №2

let count = 0;
for(index = 0; index < ourArray.length; index++) {
    let earlierValue  = ourArray[index-1];
    let presentValue = ourArray[index];
    let subsequentValue   = ourArray[index+1];

    if(presentValue === earlierValue || presentValue === subsequentValue) {
        count++;
    }
}

In this scenario, the value of count would be 2.

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