JavaScript: Check downward trend, array of integers

JavaScript Math: Exercise-93 with Solution

Check Downward Trend in Array

Write a JavaScript program to check if an array of integers has a downward trend or not.

Test Data:
([1, 3, 4, 7, 9, 10, 11]) -> false
([11, 10, 9, 7, 4, 3, 2, 0]) -> true
([1, 0, -2, -3, -12]) -> true

Sample Solution:

JavaScript Code:

/**
 * Function to check if the elements in the array are in descending order.
 * @param {number[]} nums - The array to be checked.
 * @returns {boolean} - Returns true if the array is in descending order, false otherwise.
 */
function test(nums) {
    return nums.every((item, i) => item > nums[i + 1] || item === nums[nums.length - 1]);
}

// Test cases
let nums = [1, 3, 4, 7, 9, 10, 11];
console.log("n = " + nums);
console.log("Process: " + test(nums));
nums = [11, 10, 9, 7, 4, 3, 2, 0];
console.log("n = " + nums);
console.log("Process: " + test(nums));
nums = [1, 0, -2, -3, -12];
console.log("n = " + nums);
console.log("Process: " + test(nums));

Output:

n = 1,3,4,7,9,10,11
 process: false
n = 11,10,9,7,4,3,2,0
 process: true
n = 1,0,-2,-3,-12
 process: true

Flowchart:

Live Demo:

See the Pen javascript-math-exercise-93 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that checks if an array of integers is strictly decreasing by comparing each element to the next.
• Write a JavaScript function that uses the every() method to verify that every element is greater than its successor.
• Write a JavaScript function that iterates over an array and returns true if a downward trend is detected.
• Write a JavaScript function that handles arrays with a single element or empty arrays appropriately when checking for trends.

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