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Basic Data Types

Python basic data types include:

  • Integer: Numbers without decimal points.
  • Float: Numbers with decimal points.
  • String: A sequence of characters enclosed in single quotes or double quotes.
  • Boolean: Represents True or False.
  • None: Represents empty value.


Define 5 variables to represent a person's payslip, including: name, month, salary, whether they have perfect attendance, and project team.

JavaScript implementation

let name = 'Bob' // string
let month = 12 // number
let salary = 10000.12 // number
let isPerfectAttendance = true // boolean
let team = null // null
console.log(typeof name) // Get the type of the variable

Python implementation

name = 'Bob' # str
month = 12 # int
salary = 10000.12 # float
is_perfect_attendance = True # bool
team = None # None
print(type(name)) # Get the type of the variable

Code Highlight

  • Python has two types of number types, int for integers and float for floating-point numbers, while JavaScript uses the number type for both integers and floating-point numbers.
  • Python uses None to represent empty, while JavaScript uses null.
  • Python does not have a type similar to JavaScript's undefined.
  • Python uses the built-in function type() to get the variable type, while JavaScript uses the typeof keyword.

Difference Quick View

Integerlet myInt = 10;
let myInt = Number(10);
my_int = 10
Floatlet myFloat = 3.14;
let myFloat = Number(3.14);
my_float = 3.14
Stringlet myStr = "Hello World";my_str = "Hello World"
Booleanlet myBool = true;
let myBool = false;
my_bool = True
bool_val = False
Nonelet myNull = null;my_none = None

String is one of the most widely used data types in programming languages, mastering them can greatly simplify programming. Here are the common string APIs in JavaScript and Python:

Get lengthmyStr.lengthlen(my_str)
ConcatenatemyStr1 + myStr2my_str1 + my_str2
SlicemyStr.slice(start, end)my_str[start:end]
ReplacemyStr.replace(old, new)my_str.replace(old, new)
Convert to uppercase and lowercasemyStr.toUpperCase()
Count occurrences of a substringmyStr.split(substring).length - 1my_str.count(substring)
Check if a string starts with a specified character(s)myStr.startsWith(prefix)my_str.startswith(prefix)
Check if a string ends with a specified character(s)myStr.endsWith(suffix)my_str.endswith(suffix)
Trim whitespace from both ends of a stringmyStr.trim()my_str.strip()
Center align a string with a specified
Capitalize the first letter of the first wordmyStr.replace(myStr[0], myStr[0].toUpperCase())my_str.capitalize()
Capitalize the first letter of each wordmyStr.replace(/(^\w{1})|(\s+\w{1})/g, s => s.toUpperCase())my_str.title()