 # 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>
<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>
<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: 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.

What is the difficulty level of this exercise?

﻿

## 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