JavaScript: Extract a specific number of characters from a string

Last update on May 30 2022 09:59:27 (UTC/GMT +8 hours)

JavaScript String: Exercise-4 with Solution

Write a JavaScript function to extract a specified number of characters from a string.

Pictorial Presentation:

JavaScript: Extract a specific number of characters from a string

Test Data :
console.log(truncate_string("Robin Singh",4));
"Robi"

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Extract a specific number of characters from a string</title>
</head>
<body>
</body>
</html>

JavaScript Code:

truncate_string = function (str1, length) {
  
    if ((str1.constructor === String) && (length>0)) {
        return str1.slice(0, length);
    }
};
console.log(truncate_string("Robin Singh",4));

Sample Output:

Robi

Flowchart:

Live Demo:

See the Pen JavaScript Extract a specific number of characters from a string - string-ex-4 by w3resource (@w3resource) on CodePen.

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Next: Write a JavaScript function to convert a string in abbreviated form.

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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