JavaScript: Create a variable using a user-defined name

JavaScript Basic: Exercise-13 with Solution

Create Variable with User-Defined Name

Write a JavaScript exercise to create a variable using a user-defined name.

This JavaScript exercise involves creating a variable with a name provided by the user dynamically during runtime. It typically utilizes the eval() function or the object bracket notation window[name] to achieve this dynamic variable creation based on user input. However, it's important to handle user input securely to prevent code injection vulnerabilities.

Sample Solution:

JavaScript Code:

// Declare a variable named var_name and assign it the string 'abcd'
var var_name = 'abcd';

// Declare a variable named n and assign it the number 120
var n = 120;

// Assign the value of n to the property named 'abcd' of the 'this' object
this[var_name] = n;

// Log the value of the property 'abcd' of the 'this' object to the console
console.log(this[var_name]); 

Output:

120

Live Demo:

See the Pen javascript-object-exercise-13 by w3resource (@w3resource) on CodePen.

ES6 Version:

// Declare a constant variable named var_name and assign it the string 'abcd'
const var_name = 'abcd';

// Declare a constant variable named n and assign it the number 120
const n = 120;

// Assign the value of n to the property named 'abcd' of the 'this' object
this[var_name] = n;

// Log the value of the property 'abcd' of the 'this' object to the console
console.log(this[var_name]);

For more Practice: Solve these Related Problems:

• Write a JavaScript program that prompts the user for a variable name and value, then creates the variable dynamically.
• Write a JavaScript program that stores user-defined variable names and corresponding values in an object.
• Write a JavaScript program that creates a variable using a user-specified name via eval() and then logs its value.

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