TOML configuration syntax tutorials with examples

TOML Syntax

The TOML file contains the documents each document contains the syntax specified as per TOML-supported rules. Each document or line contains key and value pairs Following is the syntax

key= "value"

key and value pair separate by equal sign and value must be double quotes Key of type string which accepts characters/ASCII codes/numbers/dashes and underscores

valid keys in TOML

Following are valid keys in TOML file content.

key="value"
test_key="value"
956="value"
key-1="value"
 key = "value" #keys with spaces are allowed
"key" = "value" # quoted keys are valid
dev.db.url="localhost" # keys containing dotted symbols are allowed for grouping

Invalid keys

value without keys are not allowed, for example, =“without key”
duplicate keys are not allowed

value types

values accept of types string, integer, Float, Boolean, Date types, Array, and tables only

TOML data key and value pair rules

value must be enclosed in double quotes
key and value pair declared in single line only
spaces before or after key and value pairs are ignored
the key is of type string and value supports limited values of different types
new line must be followed by key and value pairs in a single line
if the value is not declared, the default value is INVALID

How to declare comments in the toml file.

Like a programming language, It supports comments. Comments are usually ignored by runtime interpreters. Comments are used to specify the explanation of the configuration data. The hash symbol used for specifying comments at the starting character in the line

# This is the comment
environment="development"

It supports single-line comments and does not support multi-line comments if you want to specify the multiple lines, each line is marked with the # symbol

TOML - Syntax