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JavaScript: Find the number of even values in sequence before the first occurrence of a given number

JavaScript Basic: Exercise-110 with Solution

Write a JavaScript program to find the number of even values in sequence before the first occurrence of a given number.

Sample sequence = [1,2,3,4,5,6,7,8]
Given number: 5
Output: 2

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title> Find the number of even values in sequence before the first occurrence of a given number</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function find_numbers(arr_num, num) {
    var result = 0;
    for (var i = 0; i < arr_num.length; i++)
    {
        if (arr_num[i] % 2 === 0 && arr_num[i] !== num) {
            result++;
        }
        if (arr_num[i] === num) 
        {
            return result;
        }
    }
    return -1;
}

console.log(find_numbers([1,2,3,4,5,6,7,8], 5))
console.log(find_numbers([1,3,5,6,7,8], 6))

Sample Output:

2
0

Flowchart:

Flowchart: JavaScript - Find the number of even values in sequence before the first occurrence of a given number

ES6 Version:

function find_numbers(arr_num, num) {
    let result = 0;
    for (let i = 0; i < arr_num.length; i++)
    {
        if (arr_num[i] % 2 === 0 && arr_num[i] !== num) {
            result++;
        }
        if (arr_num[i] === num) 
        {
            return result;
        }
    }
    return -1;
}

console.log(find_numbers([1,2,3,4,5,6,7,8], 5))
console.log(find_numbers([1,3,5,6,7,8], 6))

Live Demo:

See the Pen javascript-basic-exercise-110 by w3resource (@w3resource) on CodePen.


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Next: Write a JavaScript program to check a number from three given numbers where two numbers are equal, find the third one.

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JavaScript: Tips of the Day

Classes/function constructors

class Person {
  constructor() {
    this.name = 'Owen';
  }
}

Person = class AnotherPerson {
  constructor() {
    this.name = 'Eddie';
  }
};

const member = new Person();
console.log(member.name);

We can set classes equal to other classes/function constructors. In this case, we set Person equal to AnotherPerson. The name on this constructor is Eddie, so the name property on the new Person instance member is "Eddie".

Ref: https://bit.ly/3jFRBje