Javascript Code To Perform Linear Search

Linear search consists of iterating over the data structure one value at a time and checking if that value is the one we’re looking for. It’s probably the most intuitive kind of search and the best we can do if the data structure we’re using isn’t ordered.

Let’s say we have an array of numbers and for this array we want to write a function that takes a number as the input and returns that number’s index in the array. In case it doesn’t exist in the array, it will return -1. A possible approach could be the following:

 

const arr = [1,2,3,4,5,6,7,8,9,10]

const search = num => {
    for (let i = 0; i < arr.length; i++) {
        if (num === arr[i]) return i
    }
    return -1
}

console.log(search(6)) // 5
console.log(search(11)) // -1