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JavaScript: Swap the first and last elements of a given array of integers

JavaScript Basic: Exercise-80 with Solution

Write a JavaScript program to swap the first and last elements of a given array of integers. The array length should be at least 1.

Pictorial Presentation:

JavaScript: Swap the first and last elements of a given array of integers.

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JavaScript program to swap the first and last elements of a given array of integers. The array length should be  at least 1.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function swap(arra) {
    [arra[0], arra[arra.length - 1]] = [arra[arra.length - 1], arra[0]];
    return arra;
}
console.log(swap([1, 2, 3, 4]));  
console.log(swap([0, 2, 1]));  
console.log(swap([3])); 

Sample Output:

[4,2,3,1]
[1,2,0]
[3]

Flowchart:

Flowchart: JavaScript - Swap the first and last elements of a given array of integers

ES6 Version:

function swap(arra) {
    [arra[0], arra[arra.length - 1]] = [arra[arra.length - 1], arra[0]];
    return arra;
}
console.log(swap([1, 2, 3, 4]));  
console.log(swap([0, 2, 1]));  
console.log(swap([3])); 

Live Demo:

See the Pen JavaScript - swap the first and last elements of a given array of integers - basic-ex-80 by w3resource (@w3resource) on CodePen.


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Previous: Write a JavaScript program to test if a given array of integers contains 30 and 40 twice.
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JavaScript: Tips of the Day

Converts a string to title case

Example:

const toTitleCase = str =>
  str
    .match(/[A-Z]{2,}(?=[A-Z][a-z]+[0-9]*|\b)|[A-Z]?[a-z]+[0-9]*|[A-Z]|[0-9]+/g)
    .map(x => x.charAt(0).toUpperCase() + x.slice(1))
    .join(' ');
console.log(toTitleCase('some_database_field_name')); // 'Some Database Field Name'
console.log(toTitleCase('Some label that needs to be title-cased')); // 'Some Label That Needs To Be Title Cased'
console.log(toTitleCase('some-package-name')); // 'Some Package Name'
console.log(toTitleCase('some-mixed_string with spaces_underscores-and-hyphens')); // 'Some Mixed String With Spaces Underscores And Hyphens' 

Output:

"Some Database Field Name"
"Some Label That Needs To Be Title Cased"
"Some Package Name"
"Some Mixed String With Spaces Underscores And Hyphens"