JavaScript: Find the longest string from a given array

JavaScript Basic: Exercise-125 with Solution

Find Longest String in Array

Write a JavaScript program to find the longest string in a given array.

Visual Presentation:

Sample Solution:

JavaScript Code:

// Function to find the longest string in an array
function longest_str_in_array(arra) {
  var max_str = arra[0].length; // Initialize max_str with the length of the first string
  var ans = arra[0]; // Initialize ans with the first string

  // Loop through the array starting from the second element
  for (var i = 1; i < arra.length; i++) {
    var maxi = arra[i].length; // Get the length of the current string

    // Compare the length of the current string with max_str
    if (maxi > max_str) {
      ans = arra[i]; // If current string is longer, update ans
      max_str = maxi; // Update max_str with the new maximum length
    }
  }

  return ans; // Return the longest string found
}

// Testing the function with different arrays
console.log(longest_str_in_array(["ab", "a", "abcd"])); // Output: "abcd" (Longest string in the array)
console.log(longest_str_in_array(["ab", "ab", "ab"])); // Output: "ab" (All strings are of equal length) 

Output:

abcd
ab

Live Demo:

See the Pen javascript-basic-exercise-125 by w3resource (@w3resource) on CodePen.

Flowchart:

ES6 Version:

// Function to find the longest string in an array
const longest_str_in_array = (arra) => {
  let max_str = arra[0].length; // Initialize max_str with the length of the first string
  let ans = arra[0]; // Initialize ans with the first string

  // Loop through the array starting from the second element
  for (let i = 1; i < arra.length; i++) {
    let maxi = arra[i].length; // Get the length of the current string

    // Compare the length of the current string with max_str
    if (maxi > max_str) {
      ans = arra[i]; // If current string is longer, update ans
      max_str = maxi; // Update max_str with the new maximum length
    }
  }

  return ans; // Return the longest string found
}

// Testing the function with different arrays
console.log(longest_str_in_array(["ab", "a", "abcd"])); // Output: "abcd" (Longest string in the array)
console.log(longest_str_in_array(["ab", "ab", "ab"])); // Output: "ab" (All strings are of equal length)

For more Practice: Solve these Related Problems:

• Write a JavaScript program that iterates through an array of strings and returns the longest one, handling edge cases with empty arrays.
• Write a JavaScript function that uses the reduce() method to determine the longest string in an array, returning the first occurrence in case of ties.
• Write a JavaScript program that compares the lengths of strings in an array and outputs the string with maximum length after validation.

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