convert string to number javascript

Convert String to Number JavaScript and Best 11 Different Methods

String to number conversion is a basic concept in JavaScript that will often be needed when dealing with user input, parsing data, convert string to number javascript, or performing mathematical operations. JavaScript provides several methods to achieve this goal that will allow developers to seamlessly work with numeric data stored as strings.

The purpose of the following article in “Thinkwrite.com Technology Blog” is to provide a comprehensive guide on how to convert string to number javascript programming language. By the end of this article, readers will have a clear understanding of the various techniques for performing this procedure. Mastering this concept is critical for any JavaScript programmer to ensure accurate data processing and String manipulation in JavaScript.

How to convert string to number javascript?

There are many methods to convert a string variable to a number in JavaScript, most of which are focused on using various JavaScript functions and performing mathematical operations on strings (String | String). In this context, “convert string to number javascript” it is very important that the user chooses the appropriate method based on their specific needs and data type to ensure accurate and expected results in JavaScript applications. With the help of these methods like “convert string to number javascript”, the user can effectively manage string to number javascript conversion in different programming situations. The methods discussed regarding “convert string to number javascript” in the following article are as follows:

  1. Use the function Number()
  2. Use the function parseInt()  ‎
  3. Use the function pressFloat()
  4. Use the operator unary plus (+)  ‎
  5. Multiply string by number 1
  6. Splitting a string into a number 1
  7. Subtract the number 0 from the field
  8. Use the operator bitwise NOT (~).
  9. Use the function Math.floor()
  10. Use the function Math.ceil()
  11. Using the function Math.round()

What are the best ways to convert string to number javascript?

Each method has its own characteristics and is suitable for different scenarios. Some methods, such as parseInt and parseFloat, are explicitly designed to convert strings to numbers, while others, such as the bitwise NOT operator, are unconventional ways to achieve the same result. In the following, all the mentioned methods will be taught.

Convert string to number javascript using Number function

In JavaScript, you can use the function Number () to Convert string to number. This function is a convenient and simple way to perform such conversions, the steps of this conversion are given below. For this purpose, first, a string variable called quantity that amount 12 and is defined as follows:

const quantity = "12";

If the variable type using the operator type of Be checked, type string returns:

console.log(typeof quantity); // Output: "string"

The output of the above command in the console is as follows:

convert string to number javascript

To convert a string to a number in JavaScript, you must simply use the function Number () used as follows:

const quantityAsNumber = Number(quantity);

Now, if the type quantityAsNumber Check again, this time number, indicating that the conversion was successful. The output will be as follows:

convert string to number javascript

It is important to note that if the user wants to convert string to number javascript, but this string cannot be interpreted as a number, the function Number () the amount of NaN The following example illustrates this:

console.log(Number("awesome")); // Output: NaN

The output of the above code in the browser console is as follows:

convert string to number javascript

Function Number() It is a valuable tool for converting strings to numbers in JavaScript. However, caution should be exercised when using it, especially if we have inputs that represent valid numeric values, as it may result in output NaN become to this end, user input must always be validated or checks performed to ensure that the string can be safely executed before using the function. Number () Convert to a number to avoid unexpected behavior in the code.

Convert string to number javascript using parseInt function

Another way to convert a string to a number in JavaScript is to use a function parseInt() Is. Unlike the function Number (), parseInt() Allows the user to specify an optional base type that represents the base in the number system (i.e., the number system used to count and express values). Following is an example to show how to convert string to number using parseInt() It is given that for this purpose it is assumed that the string again quantity Has value 12 Is:

const quantity = "12";

To convert string quantity to the number, from the function parseInt() In the basis 10  is used to represent the decimal system:

const quantityAsNumber = parseInt(quantity, 10);

Variable quantityAsNumber Now has a numerical value 12 Is. If its type using the operator type of review number returns:

console.log(typeof quantityAsNumber); // Output: "number"

The output of the above code in the browser console is as follows:

convert string to number javascript

Now, let’s check if the try variable quantity The amount 12.99 Change and from parseInt() What happens when it is used to convert?

const quantity = "12.99";
console.log(parseInt(quantity, 10));

The output of the above code in the browser console is as follows:

convert string to number javascript

The result of using parseInt() with amount 12.99 number 12 is, no 12.99 . This behavior occurs because parseInt() will convert the string to an integer. If you need to save decimals and get floating point numbers, you should instead parseInt() From pressFloat()  used

In the rest of this article, how to convert a string to number in JavaScript with pressFloat() will also be examined. Function parseInt() It is suitable to convert the string to an integer using a specific base, and as mentioned, if you need to store decimal values, you should instead use pressFloat() used. It should be noted that to ensure accurate results in JavaScript applications, the appropriate conversion method must be selected on a case-by-case basis.

Convert string to number javascript using parseFloat

In JavaScript, the function pressFloat() Used to convert string to floating point number. Unlike parseInt() which converts the string to an integer, pressFloat() It will retain decimal values, making it suitable for handling numbers with fractional values.

Below is how to use pressFloat() Checked to convert string to number javascript. To start, let’s create a string variable called quantity with amount 12.99 consider:

const quantity = "12.99";

by using pressFloat() , can string quantity converted to a floating point number as follows:

const quantityAsFloat = parseFloat(quantity);

Variable quantityAsFloat Now has a floating point number 12.99 Is. If its type using the operator type of Review, number returns:

console.log(typeof quantityAsFloat); // Output: "number"

The output of the above command in the browser console will be as follows:

convert string to number javascript

It is important to note that pressFloat() Handles trailing spaces and strings well and still converts it to a floating point number:

const quantity = "   12.99    ";
console.log(parseFloat(quantity)); // Output: 12.99

However, if the first character of the string cannot be converted to a number, pressFloat() the amount of IN The following example illustrates this:

const quantity = "F12.99";
console.log(parseFloat(quantity)); // Output: NaN

The output of the above code in the browser console is as follows:

convert string to number javascript

In the whole function pressFloat() It is a valuable tool for converting string to floating point number in JavaScript. This function accurately handles decimal values ​​and will handle leading or trailing whitespaces well. However, be careful about passing strings with invalid numeric representations when using this function because IN returns the

Convert String to Number using unary operator +

In JavaScript, a string can be converted to a number using the “unary plus operator”. When the operator + Placed before the (string) operand, it tries to convert the string to a numeric value. Below is an example to express the conversion of string to number in JavaScript with the unary operator + is brought

const quantity = "12";
console.log(+quantity); // Output: 12........

By applying the operator + to string quantity It can be converted to a numerical value as follows:

console.log(+quantity); // Output: 12

field quantity Now successfully converted to number. If the result type using the operator type of Review number returns:

console.log(typeof +quantity); // Output: "number"

The output of the above command in the browser console is as shown below:

convert string to number javascript

The addition unary operator can also handle floating-point numbers in strings, as the following example illustrates:

const quantity = "12.99";
console.log(+quantity); 

The output of the above example in the browser console is as follows:

convert string to number javascript

If the string cannot be converted to a number, result NaN will be returned:

const quantity = "awesome";
console.log(+quantity); 

The output of the above code in the browser console is as follows:

convert string to number javascript

The addition unary operator provides a concise and simple way to convert strings to numeric values ​​in JavaScript. This method can handle both integers and floating-point numbers, but if the string is non-numeric, NaN it will be obtained. As with other string-to-number conversion methods in JavaScript, it is important to ensure that the input data is valid before using the unary operator to avoid unexpected results in JavaScript projects.

Other methods of converting strings to numbers in JavaScript

So far, we have described different ways to convert string to number javascript. But in the continuation of this article from thinkwriteway blog, we will also examine other methods of convert string to number javascript.

How to convert string to number javascript by multiplying string by number 1

In JavaScript, a string can be converted to a number using basic math operations. The technique of multiplying a string by a number 1 One of these methods is to convert string to number javascript. This simple technique allows the user to obtain a numeric representation of the string. To demonstrate this let’s use the same string variable quantity with amount 12 Let’s start working. To convert string quantity In numbers, it can be 1 struck As in the following example:

const quantity = "12";
console.log(quantity * 1); // Output: 12

When the amount quantity in number 1 is multiplied, JavaScript internally converts the string to a number before performing the math operation. As a result, console no 12 displays For this purpose, if the type of the result using the operator type of let’s check number returns:

console.log(typeof (quantity * 1)); // Output: "number"

The output of the above code in the browser console is as follows:

convert string to number javascript

Again, if the string cannot be converted to a number, the math operation will not work NaN returns:

const quantity = "awesome";
console.log(quantity * 1); // Output: NaN

The output of the above code in the browser console is as follows:

convert string to number javascript

This method also has a user for floating point numbers as shown in the example below.

const quantity = "10.5";
console.log(quantity * 1); // Output: 10.5

The output of the above code in the browser console is as follows:

convert string to number javascript

Multiply string by number 1 It’s an efficient way to convert it to a numeric value in JavaScript. As with other string-to-number methods in JavaScript, it’s important to ensure that the string receives a valid numeric input before using this technique, as non-numeric strings result in NaN be. Proper use of this method can be useful for various data manipulation tasks in JavaScript coding and exercises.

How to convert string to number javascript by dividing string by number 1

Another way to convert string to number javascript is to divide string by the number 1. Similar to the previous multiplication method, this technique uses automatic JavaScript type conversion to achieve the desired result.

const quantity = "10.5";
console.log(quantity / 1); 
console.log(typeof (quantity / 1));

The output of the above code in the browser console is as follows:

convert string to number javascript

All the things said for the method of convert string to number javascript by multiplying that string by a number 1, for the method of dividing that string into a number 1 It is also true and there is no need for further explanations in this regard.

Convert string to number javascript by subtracting zero from the string

Another mathematical operation in JavaScript that can be used to convert a string into a number is the subtraction operation. 0 It is from the field in question that to show this concept, the same example above is used this time in the following syntax:

const quantity = "19";
console.log(quantity - 0); 
console.log(typeof (quantity - 0)); // Output:

when 0 To subtract from the value of the given string as in the above example, JavaScript automatically converts the string to a number before performing the subtraction operation. As a result, console no 19 displays If the result type using the operator type of Check, again the browser console number returns the Like the picture below:

convert string to number javascript

As with the previous methods, if the string cannot be converted to a number, the subtraction operation will not work NaN returns the This method is another convenient way to convert a string to a numeric value in JavaScript. Using this approach, when necessary, can simplify code and facilitate numeric operations with strings in JavaScript.

Convert string to number javascript with bitwise NOT operator

In JavaScript, you can use the bitwise operator NOT (~) » Convert string to number. operator NOT Reverses the bits of its operand and converts the result to a 32-bit signed integer.

console.log(~19);

The output of the above code in the browser console is as follows:

convert string to number javascript

However, the more common way to convert a string to a number is to use two bitwise operators (~~) which effectively performs the following operations:

‎-(x + 1)

Below we will review this method together. For this purpose, it is assumed that the field quantity Has value 19 Is.

const quantity = "19";

To convert string quantity to number using bitwise operator NOT, can be from two bitwise operators NOT used as follows:

console.log(~~quantity);

Two bitwise operators NOT By performing the action -(x + 1) The string is converted into a number, which is a number 19 produces in the output. This time, if the result type using the operator type of Check the output number will be:

console.log(typeof ~~quantity); 

The output of the above command in the browser console this time will be as follows:

convert string to number javascript

This method does not work for floating-point numbers because the result will be an integer, and this is because bitwise operations apply to integers:

const quantity = "19.99";
console.log(~~quantity); // Output: 19

If the user tries to use this method on non-numeric characters, the result 0 will be because bit operations NOT Cannot convert non-numeric strings.

const quantity = "awesome";
console.log(~~quantity); // Output: 0

Also, when using the operator NOT It is important to be careful when converting string to number in JavaScript because it has limitations. It may start to break for values ​​considered too large for a 32-bit signed integer, as in the following example:

const quantity = "2700000000";
console.log(~~quantity); 

The output of the above command this time in the browser console is as follows:

convert string to number javascript

while the bitwise operator NOT Can be used to convert string to number javascript, not the most common or recommended method due to limitations and potential problems with large values. It’s better to use the other conversion methods discussed earlier because they provide more predictable and reliable results for string-to-number conversions in most cases.

Convert string to number javascript using Math.floor function

In JavaScript, you can use the function, Math.floor() Convert string to number javascript. This operation truncates the decimal to the closest whole number downwards. In fact, this function will round the decimal number to the bottom of that number. However, it is important to note that, Math.floor() It is not primarily used to convert strings to numbers, but is used for mathematical rounding operations.

const quantity = "13.4";
console.log(Math.floor(quantity)); 
console.log(typeof Math.floor(quantity)); // Output: "number"

The output of the above code in the browser console is as follows:

convert string to number javascript

As in the previous examples, if the user tries to Math.floor() Use on non-numeric characters, result NaN will be because the function only expects numeric input:

const quantity = "awesome";
console.log(Math.floor(quantity)); // Output: NaN

While it is possible to Math.floor() Used to perform string to number conversion in JavaScript, but this is not the usual method for this purpose. This function is primarily designed for mathematical rounding operations, and using it simply to convert strings to numbers may lead to unexpected results. Instead, you should use more suitable techniques for this purpose, which are taught above.

Convert string to number javascript using Math.ceil function

Use the function Math.ceil() It can also convert string to number javascript, and in this case the number will be rounded to the nearest integer. In fact, in this method rounding is up and the number will be rounded to the ceiling of that decimal number. To show how to use Math.ceil() , let’s work with a string variable called quantity with amount 7.18 Let’s begin:

const quantity = "7.18";
console.log(Math.ceil(quantity));
console.log(typeof Math.ceil(quantity)); 

The output of the above code in the browser console is as follows:

convert string to number javascript

All conditions are subject Math.floor() for the function Math.ceil() It also applies.

Convert string to number javascript using Math.round function

Similarly, we can use the function Math.round() It is used to round the number to the nearest whole number, and it is actually a method to round and convert the string to a number. This method of rounding the number if the first number is the decimal part of 5  If it is up, it rounds the number towards the ceiling and otherwise towards the bottom.

const quantity = "6.3";
console.log(Math.round(quantity));

By applying the function Math.round() on string quantity, it can be converted into a number and rounded to the nearest whole number. Now if the same method above this time for the amount 6.5 What does the value change when applied?

const quantity = "6.5";
console.log(Math.round(quantity)); // Output: 7

In general, we can use the function, Math.round() It is used to round the number to the nearest integer in JavaScript, and it also has a user to convert the number to a string. However, it is important to note that when using this function with strings, it first convert string to number javascript before performing the rounding operation. Math.round() It is useful for mathematical rounding operations and is not usually used to convert strings to numbers.

Conclusion

Convert string to number javascript is a common and useful operation that users and programmers are required to do to face various scenarios. For this purpose, there are different ways that allow the user to do this in the easiest possible way. Most of the existing methods for this purpose are done either by using special functions or by using mathematical operations.

In the above article from the thinkwriteway blog, 11 different methods for convert string to number JavaScript were reviewed. Each method has its own advantages and considerations, and choosing the right method depends on the specific application and desired behavior.

If you seek further information about the Convert String to Number JavaScript and Best 11 Different Methods or have any inquiries regarding our blog, please don’t hesitate to contact us via email at info@thinkwriteway.com

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