How To Convert Integer To String In Javascript

JavaScript is a popular scripting language, a task that many JavaScript programmers encounter when coding is the conversion of data types, with the most common conversion being integers to strings.

This conversion is indispensable when we wish to display numerical values as text or when we want to concatenate a string with a number.

So, in this article, we’ll provide you with deep knowledge about conversion of integer to string.

Why is there a need to convert int to string in Javascript

Here are the reasons to convert int to string:

• Data Manipulation: The data type of a variable can change throughout the code. This flexibility can be both helpful and challenging.
• User Input Validation: When working with user input, you need to convert an integer to string for validation.
• Output Formatting: In JavaScript, you may need to format output to display numbers in a certain way.

Different Approaches to convert int to string in Javascript

There are several methods to convert integers to string in javascript.

1. Using the toString() method
2. Using the String() constructor
3. Using Concatenation

Different methods to convert integer to string in Javascript

Method 1: Using toString() method

The “toString()” function in JavaScript is a feature that’s already included in the language. This function allows you to get a string representation of an object.

let myNumber = 42;
let myString = myNumber.toString();
console.log(typeof myString); // Output: string
console.log(myString); 

Output:

String
42

Explanation:

• We first declare a variable myNumber and assign it the value 42.
• After that we use the toString() method to convert myNumber to string value, and assign the result to a new variable called myString.
• we use console.log() to output the type of myString and the value of myString.

Method 2: Using String() constructor method

In JavaScript, the String() constructor method is used to create a new string object. It can be called with or without the new keyword and it can accept one or more arguments. If no argument is provided an empty string is created.

let num = 123;
let str = String(num);
console.logln(typeof str);console.log(str);

Output:

String
123

Explanation:

• In this code, first we declare a variable num with the value 123, which is an integer.
• We then use the String() constructor method to convert this integer to a string and assign the result to a new variable called str.
• Then we log the type of the str variable using the typeof operator, which will output “string”, indicating that str is now a string data type.
• We log the value of str itself, which will output “123”, the string representation of the original integer value.

Method 3: Using Concatenation

You simply combine an empty string value with the number, and the result will be the number written as String.

let num = 42; // integer
let str = ''; // empty string


str = num + '';

console.log(typeof num); // output: number
console.log(typeof str); // output: string
console.log(str);

Output:

number
string
42

Explanation:

• We first declare an integer variable num with a value of 42.
• To convert the integer number to string type, we have to concatenate it with the empty string value ”.
• This convert integer number to string type, if any value concatenated with a string will also be converted to a string value.
• We use the typeof operator to verify that num is an integer and str is a string.
• We also log the value of str to the console to verify that the conversion worked correctly.

Best Approach for converting an integer to a string in Javascript.

toString() method is the best method to convert integer to string in javascript.

1. Simplicity: The toString() method is a function in JavaScript which is easy to use and it requires only one line to convert an integer to string type.
2. Flexibility: The toString() method is used with integer value so that it can convert into string value.
3. Control: The toString() method offers a way of controlling the output of converting the integer into string type in javascript.

Sample Problem for Converting Integer into String in javascript.

Sample Problem 1:

Suppose you have a list of integers and want to convert all integers in string then write a code that takes input integers and converts them into string in javascript.

Solution:

• The prompt() function is used to display a dialog box where the user can enter an integer. The value entered by the user is stored in the integerInput variable as a string.
• The parseInt() function is used to convert the string value of integerInput to an actual integer. This is necessary because the toString() method can only be called on an actual integer, not a string.
• The toString() method is called an integerInput to convert the integer to a string. The resulting string value is stored in the stringOutput variable.

The console.log() function is used to display the string representation of the integer in the console. 

let integerInput = parseInt(prompt("Enter an integer: "));
let stringOutput = integerInput.toString();
console.log("The string representation of the integer is: " + stringOutput);

Output

Enter an integer: 12
The string representation of the integer is: 12

Sample Problem 2:

Suppose you are making a function in which you are calculating factorial of 5 and then the result comes in integer and then you need to convert it into string because of further process.

Solution:

• We define a function called factorial which takes a single parameter n. This function uses recursion to calculate the factorial of n.
• We call the factorial function with the argument 5, which calculates the factorial of 5 using the recursive algorithm defined in the function. The result of this calculation is assigned to the variable result.
• We use the String() constructor method to convert the value of result from an integer to a string. This is done by calling String(result) and assigning the resulting string to the variable strResult.
• We output the value of strResult to the console using console.log(). This prints the string representation of the factorial of 5, which is “120”, to the console.

function factorial(n) {
  if (n < 0) {
    return -1;
  } else if (n == 0) {
    return 1;
  } else {
    return n * factorial(n - 1);
  }
}

let result = factorial(5); // calculates factorial of 5, which is 120
let strResult = String(result); // converts the result to a string

console.log(“output of 120 as a ” + typeof(strResult));

Output:

output of 120 as a string

Sample Problem 3:

Suppose you are working on a project in which you are calculating hcf of two 35 and 23 respectively,  and after getting hcf in integer then convert it into string so that it can be compatible with the for() loop.

Solution:

1. Declare variables num1, num2, and hcf to store the two input numbers and the HCF value respectively.
2. Use a loop to iterate from 1 to the smaller of the two numbers and check if both num1 and num2 are divisible by the current iteration number i. If they are, update the hcf variable to store the current iteration value i, which is the highest common factor of num1 and num2.
3. Convert the hcf value to a string by using the concatenation method. This can be done by adding an empty string “” before the hcf variable, which will coerce the number value to a string value.
4. Output the result in a string format that combines the HCF value with any additional text or formatting required.

let num1 = 35;
let num2 = 45;
let hcf = 1;

for(let i = 1; i <= num1 && i <= num2; i++) {
  if(num1 % i == 0 && num2 % i == 0) {
    hcf = i;
  }
}

let hcfString = "" + hcf;

console.log("The HCF of " + num1 + " and " + num2 + " is " + hcfString + ", which is a string.");

Output:

The HCF of 35 and 45 is 5, which is a string.

Conclusion

Converting an integer into a string in JavaScript is a straightforward process that can be accomplished using various methods.

The most commonly used methods include using the toString() method, concatenation with an empty string, and using the String() function.

All these methods are simple and effective, and the choice of method depends on the user’s preference and the specific use case.