How do you console.log() in linear search algorithm?

[saejim91]

How would you console.log(“Found”) and (“not Found”) based on linear search algorithm in JS?

//  we have number of items
const items = [2, 5, 3, 6, 7, 10, 34, 63, 20, 14];

// the number we r looking for
const item = 10;

function searchItem() {
 //go over the number of items
 for (let i = 0; i < items.length; i++) {
  //if found,print found
  if (items[i] == item) {
   console.log(`Item is found, it is ${items[i]}`);
  } else {
   //   print not found, if not found
   console.log('Item not found!');
  }
 }
}

searchItem();

Problem here is, it prints out the rest of number if I put it inside the loop or printout the “Nothing found” anyway at the end.
if I break out of loop, it will print out the rest of the “not found” until the item is found.

could you guys help me out on this?

[caryaharper]

If you find the item then console.log and use the return keyword to terminate the function. Only console.log at the end of the function rather than inside the loop.

[michaelnicol]

Use some form of flag variable that exists outside of the loop. I would also print the index of the item, not the value, because the value is already known.

let flag = false;
let values = ["h", "i", "t"]
let target = "h"

function find(arr, t) {
  let indexArr = []
  for (let i = 0; i < values.length; i++) {
    if (values[i] == target) {
      console.log(`Item found at ${i}`)
      flag = true;
    }
  }
  return flag
}

let output = find(values, target)

This approach can be optimized. If I wanted to break the loop instantly and not care about telling someone the index of the value, I could use the following:

function find(arr, t) {
  let indexArr = []
  for (let i = 0; i < values.length; i++) {
    if (values[i] == target) {
      return true
    }
  }
  return false
}

let output = find(values, target)
console.log(output ? "Item Found" : "Item Not Found")

Notice how I don’t return “Item Found”, I instead return true or false. This makes it a more universal function for others to use. Strings should always be a last resort. Always try to simplify logic into Booleans or lists of pure data.

Instead of writing the following and possibly dealing with typos (etc, “Item FOund”)

if (output == "Item Found") { ...

I could simply write the following that is universal

if (output) { ...

You could also use a method that saves the index of every location of your target in the array. This would be a more efficient approach if the target is repeated, which is usually the case. This is also more useful because in a real world application, you are trying to find something and need to save the location of that item.

function find(arr, t) {
  let indexArr = []
  for (let i = 0; i < values.length; i++) {
    if (values[i] == target) {
      indexArr.push(i)
    }
  }
  return indexArr
}

let output = find(values, target)
console.log(output)
if (output.length == 0) {
  console.log(`No Results Found`)
} else {
  console.log(`Item Found`)
}

On a side not, you also could just use .indexOf() which will return a index or -1 if the item is not found.

[saejim91]

Only console.log at the end of the function will will print out that message anyway regardless of conditions.

[saejim91]

Thank You So much! This is exactly what I was looking for!