What are the differences between parseInt() and parseFloat() in JavaScript?
Alex K

In JavaScript,parseInt() andparseFloat() are built-in functions used to convert strings to numeric values. Although they serve a similar purpose, there are some key differences between them. Here's a detailed explanation of the differences: 1. Parsing Integers vs. Parsing Floats: -parseInt(): -parseInt() is used to parse and convert a string into an integer value. It extracts and returns the whole number part of the string, discarding any decimal places. -parseFloat(): -parseFloat() is used to parse and convert a string into a floating-point number value. It extracts and returns both the whole number and decimal part of the string. 2. Handling Decimal Places: -parseInt(): -parseInt() ignores any decimal places in the input string. It only returns the whole number portion, truncating any decimal values. -parseFloat(): -parseFloat() considers and preserves the decimal places in the input string. It returns the number as a floating-point value, including any decimal portion. 3. Numeric String Format: -parseInt(): -parseInt() assumes the input string is in whole number format, potentially prefixed with a sign (+/-). It stops parsing as soon as it encounters a non-numeric character or the end of the string. -parseFloat(): -parseFloat() assumes the input string may contain both whole and fractional numbers, potentially prefixed with a sign (+/-). It continues parsing until it encounters an invalid character or the end of the string. 4. NaN and Invalid Strings: -parseInt(): - If the input string cannot be parsed into an integer value,parseInt() returnsNaN (Not a Number). However, it can still return a valid number if the string starts with a valid numeric sequence. -parseFloat(): - If the input string cannot be parsed into a floating-point number,parseFloat() returnsNaN. Similarly, it can return a valid number if the string starts with a valid numeric sequence. 5. Base Radix: -parseInt(): -parseInt() allows you to specify an optional second parameter, called the radix, which indicates the base of the input string. The radix can be any integer from 2 to 36. If not specified,parseInt() assumes a radix of 10. -parseFloat(): -parseFloat() does not support the radix parameter. It always assumes a decimal (base 10) representation. Here are some examples that demonstrate the differences betweenparseInt() andparseFloat():

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const numericString = '10.45';

const parsedInteger = parseInt(numericString);      // Output: 10
const parsedFloat = parseFloat(numericString);      // Output: 10.45

const invalidString = 'Hello, World!';

const invalidInteger = parseInt(invalidString);      // Output: NaN
const invalidFloat = parseFloat(invalidString);      // Output: NaN

In these examples, the input string'10.45' is parsed using bothparseInt() andparseFloat(), resulting in the differences mentioned above. Similarly, an invalid string'Hello, World!' is also parsed, resulting inNaN values for both functions. Consider these differences when choosing betweenparseInt() andparseFloat() based on your specific use case and the desired behavior for parsing numeric strings in your JavaScript code.

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