JavaScript: Swap two halves of a given array of integers of even length
JavaScript Basic: Exercise-148 with Solution
Write a JavaScript program to swap two halves of a given array of integers of even length.
Pictorial Presentation:
Sample Solution:
HTML Code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Swap two halves of a given array of integers of even length.</title>
</head>
<body>
</body>
</html>
JavaScript Code:
function halv_array_swap(iarra) {
if (((iarra.length)%2)!=0)
{
return false;
}
for (var i = 0; i < iarra.length / 2; i++) {
var tmp = iarra[i];
iarra[i] = iarra[i + iarra.length / 2];
iarra[i + iarra.length / 2] = tmp;
}
return iarra;
}
console.log(halv_array_swap([1,2,3,4,5,6]))
console.log(halv_array_swap([1,2,3,4,5,6,7]))
Sample Output:
[4,5,6,1,2,3] false
Flowchart:
ES6 Version:
function halv_array_swap(iarra) {
if (((iarra.length)%2)!=0)
{
return false;
}
for (let i = 0; i < iarra.length / 2; i++) {
const tmp = iarra[i];
iarra[i] = iarra[i + iarra.length / 2];
iarra[i + iarra.length / 2] = tmp;
}
return iarra;
}
console.log(halv_array_swap([1,2,3,4,5,6]))
console.log(halv_array_swap([1,2,3,4,5,6,7]))
Live Demo:
See the Pen javascript-basic-exercise-148 by w3resource (@w3resource) on CodePen.
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Previous: Write a JavaScript program to compute the sum of all digits that occur in a given string.
Next: Write a JavaScript program to change the capitalization of all letters in a given string.
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JavaScript: Tips of the Day
How to insert an item into an array at a specific index (JavaScript)?
What you want is the splice function on the native array object.
arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:
var arr = []; arr[0] = "Jani"; arr[1] = "Hege"; arr[2] = "Stale"; arr[3] = "Kai Jim"; arr[4] = "Borge"; console.log(arr.join()); arr.splice(2, 0, "Lene"); console.log(arr.join());
Ref: https://bit.ly/2BXbp04
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