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JavaScript: Check whether an 'input' is a string or not

JavaScript String: Exercise-1 with Solution

Write a JavaScript function to check whether an 'input' is a string or not.

Test Data:
console.log(is_string('w3resource'));
true
console.log(is_string([1, 2, 4, 0]));
false

Pictorial Presentation:

JavaScript: Check whether an 'input' is a string or not

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Check whether an input is a string or not</title>
</head>
<body>
</body>
</html>

JavaScript Code:

is_string = function(input) {
  if (Object.prototype.toString.call(input) === '[object String]')
    return true;
  else
    return false;   
    };
console.log(is_string('w3resource'));
console.log(is_string([1, 2, 4, 0]));

Sample Output:

true
false

Flowchart:

Flowchart: JavaScript- Check whether an 'input' is a string or not

Live Demo:

See the Pen JavaScript Print an integer with commas as thousands separators - string-ex-1 by w3resource (@w3resource) on CodePen.


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Next: Write a JavaScript function to check whether a string is blank or not.

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JavaScript: Tips of the Day

JavaScript: use strict

function getAge() {
  'use strict';
  age = 21;
  console.log(age);
}

getAge();

With "use strict", you can make sure that you don't accidentally declare global variables. We never declared the variable age, and since we use "use strict", it will throw a reference error. If we didn't use "use strict", it would have worked, since the property age would have gotten added to the global object.

Ref: https://bit.ly/323Y0P6