Here you can see all data types in the MQL language.

admin
123

mentdb
123

admin
+ 3 4

mentdb
7

admin
"Hello!"

mentdb
Hello!

admin
concat "Hello " "Adam" "!"

mentdb
Hello Adam!

admin
null

mentdb
null

admin
is null null;

mentdb
1

admin
[_n_]

mentdb

admin
[_r_]

mentdb

admin
-> "[var1]" 16

mentdb
16

admin
env show;

mentdb
{
  "[var2]": "16"
}

admin
true

mentdb
1

admin
false

mentdb
0

admin
json load "keyId" "{}";

mentdb
1

admin
json doc "keyId";

mentdb
{}

admin
#This is a comment;

mentdb
This is a comment ...

admin
exception (1) ("your message ...");

mentdb
1: your message ...