How to convert a float to int in JavaScript - onlyxcodes

Saturday 27 May 2023

You are going to learn how to convert a float to an int in JavaScript in this tutorial.

Type casting in JavaScript describes the procedure of changing a value's data type. It enables you to explicitly alter a value's type so that it can be utilized in a different situation or carry out specific activities.

Convert a float to int in JavaScript

The JavaScript functions Math.floor(), Math.ceil(), and Math.round() can be used to convert a float to an integer.Â

An illustration of casting a float to an int using these techniques is as follows:

``````<html>
<title>Convert a float to int in JavaScript</title>
<body>

<script type="text/javascript">

let floatNumber = 3.14;

// Using Math.floor() - rounds down to the nearest integer

let intNumber1 = Math.floor(floatNumber);
console.log(intNumber1); // Output: 3

// Using Math.ceil() - rounds up to the nearest integer

let intNumber2 = Math.ceil(floatNumber);
console.log(intNumber2); // Output: 4

// Using Math.round() - rounds to the nearest integer

let intNumber3 = Math.round(floatNumber);
console.log(intNumber3); // Output: 3

</script>

</body>
</html>``````

floatNumber is a float having the value 3.14 in the example above.Â

The float is rounded to the nearest integer using the Math.floor() function, which gives intNumber1 the value 3.Â

The float is rounded up to the nearest integer using the Math.ceil() function, which gives intNumber2 the value 4.Â

Last but not least, the float is rounded to the nearest integer using the Math.round() function, which gives intNumber3 the value 3.

Which JS function converts decimal numbers to integer values?

The Math.floor() function in JavaScript can be used to convert decimal numbers to integer values.Â

The Math.floor() function returns the result after rounding a number to the nearest integer.

Here's an illustration:

``````<html>
<title>Which JS function convert decimal numbers to integer values</title>
<body>

<script type="text/javascript">

let decimalNumber = 3.7;

let integerValue = Math.floor(decimalNumber);

console.log(integerValue); // Output: 3

</script>

</body>
</html>``````

The integerValue variable is given the result of rounding the decimal number 3.7 to the nearest integer value using Math.floor() in the example above.Â

The result of the console.log() command is 3.

How to convert a decimal to integer in JavaScript?

Depending on the desired rounding behavior, you can use either the Math.floor() or Math.ceil() functions in JavaScript to convert a decimal value to an integer.Â

Here is an illustration of how to accomplish it:

``````<html>
<title>How to convert a decimal to integer in JavaScript</title>
<body>

<script type="text/javascript">

var decimalNumber = 3.14159;
var integerNumber = Math.floor(decimalNumber); // or Math.ceil(decimalNumber) for rounding up
console.log(integerNumber); // Output: 3

</script>

</body>
</html>``````

In the example above, the decimal number is rounded to the nearest integer using Math.floor().Â

Instead, you can use Math.ceil() to round the number up to the nearest integer.

Note:Â It should be noted that such procedures truncate any partial parts of the number and only impact the decimal part.Â

You may also use the parseInt() function to completely eliminate the decimal component without rounding:

``````<html>
<title>How to convert a decimal to integer in JavaScript</title>
<body>

<script type="text/javascript">

var decimalNumber = 3.14159;
var integerNumber = parseInt(decimalNumber);
console.log(integerNumber); // Output: 3

</script>

</body>
</html>``````

A string parameter is parsed by the parseInt() function, which then returns an integer.Â

When a decimal number is passed as a string to parseInt(), the decimal section will be truncated and the integer portion will be returned.

How to type cast to integer in JavaScript?

Use the parseInt() or Number() function in JavaScript to typecast a value to an integer. The input will be transformed into an integer by any method.

Here is a parseInt() example:

The parseInt() function is used in the code above to transform the numberString variable, which has the string "42," into an integer.

``````<html>
<title>How to type cast to integer in JavaScript</title>
<body>

<script type="text/javascript">

let numberString = "42";
let integerValue = parseInt(numberString);
console.log(integerValue); // Output: 42

</script>

</body>
</html>``````

Here is a usage case for Number():

Here, the numberString variable is changed to an integer using the Number() function.

``````<html>
<title>How to type cast to integer in JavaScript</title>
<body>

<script type="text/javascript">

let numberString = "42";
let integerValue = Number(numberString);
console.log(integerValue); // Output: 42

</script>

</body>
</html>``````

For converting numeric strings to integers, both techniques are valid.Â

Note: It's crucial to remember that parseInt() offers extra features, such as the capacity to define a radix (base) for parsing numbers in various number systems (such as binary and hexadecimal), which can be useful.

In this case, the string should be interpreted as a binary number, therefore the second argument 2 is supplied to the parseInt() function.

Remember that both methods will return NaN (Not a Number) if the supplied value cannot be transformed into an acceptable integer. It's crucial that your programming properly handles these situations.

``````<html>
<title>How to type cast to integer in JavaScript</title>
<body>

<script type="text/javascript">

let binaryString = "1010";
let binaryValue = parseInt(binaryString, 2); // Parse binary string
console.log(binaryValue); // Output: 10

</script>

</body>
</html>``````

How to convert value float in JavaScript?

JavaScript's parseFloat() function can be used to convert a value into a float.Â

Here's an illustration:

``````<html>
<title>How to convert value float in JavaScript</title>
<body>

<script type="text/javascript">

let stringValue = "3.14";
let floatValue = parseFloat(stringValue);

console.log(floatValue); // Output: 3.14
console.log(typeof floatValue); // Output: "number"

</script>

</body>
</html>``````

The string value "3.14" is converted to a float in the example above using the parseFloat() function. The variable floatValue holds the final float value.Â

The variable floatValue is then checked to see if it is of type "number," indicating that it is a float, using the typeof operator.

Note:Â Take note that parseFloat() will return NaN (Not a Number) if the string cannot be transformed into an appropriate float.Â

For instance:

In this case, the string "Hello" cannot be converted to a float, so parseFloat() returns NaN.

``````<html>
<title>How to convert value float in JavaScript</title>
<body>

<script type="text/javascript">

let invalidValue = "Hello";
let floatValue = parseFloat(invalidValue);

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

</script>

</body>
</html>``````