What is the type() function in LUA?

Overview

The LUA programming language has a number of data types. They include the following:

  • nil
  • boolean
  • number
  • string
  • function
  • table

The purpose of knowing these data types is to learn about the type function that returns a value of any of these data types.

The type() function will accept a value of any type, check for what data type it is, and return its name as a string. The type() function returns the type of its only argument set as a string.

Syntax

Let’s view the syntax of the function:

type(value)

Parameter

  • value: This is the only parameter of this function. It is the value whose data type is being checked.

Return value

The type() function returns the data type of its only argument, set as a string. These values can be any of the following:

  • "nil" (as a string, not the actual value)
  • number
  • string
  • boolean
  • table
  • function
  • thread
  • userdata

Code

In the code snippet below, we check for the data types of each variable:

--declare variables
boolVal = true;
int_value = 1024;
stringVal = "hello world";
floatVal = 12.90;
--display the data type returned for each declared value.
print(type(boolVal));
print(type(int_value));
print(type(stringVal));
print(type(floatVal));
print(type(nilVal));

Explanation

  • Line 3: We declare a boolean value.
  • Line 4: We declare an integer number value.
  • Line 5: We declare a string value.
  • Line 6: We declare a float number variable.
  • Lines 9–13: We use the type() built-in routine to get the type of the earlier declared variables and print the outcome to display.

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