Numerical Expressions 1.10
Expression 11000xl Glass Replacement
Expressions 1099 Eyeglass Frame

Regular Expressions Quick Start. This quick start gets you up to speed quickly with regular expressions. Obviously, this brief introduction cannot explain everything there is to know about regular expressions. For detailed information, consult the regular expressions tutorial. Each topic in the quick start corresponds with a topic in the.

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A Power Query M formula language query is composed of formula expression steps that create a mashup query. A formula expression can be evaluated (computed), yielding a value. The let expression encapsulates a set of values to be computed, assigned names, and then used in a subsequent expression that follows the in statement. For example, a let expression could contain a Source variable that equals the value of Text.Proper() and yields a text value in proper case.

May 02, 2014 MATH ALGEBRA 1 VIDEO LESSON - VARIABLES AND EXPRESSIONS - This Algebra 1 lesson will teach you what are variables and expressions. You will understand how variables are considered and how.
Although many values can be written literally as an expression, a value is not an expression. For example, the expression 1 evaluates to the value 1; the expression 1+1 evaluates to the value 2. This distinction is subtle, but important.

Let expression

In the example above, Text.Proper('hello world') is evaluated to 'Hello World'.

The next sections describe value types in the language.

Primitive value

A primitive value is single-part value, such as a number, logical, text, or null. A null value can be used to indicate the absence of any data.

Type	Example value
Binary	00 00 00 02 // number of points (2)
Date	5/23/2015
DateTime	5/23/2015 12:00:00 AM
DateTimeZone	5/23/2015 12:00:00 AM -08:00
Duration	15:35:00
Logical	true and false
Null	null
Number	0, 1, -1, 1.5, and 2.3e-5
Text	'abc'
Time	12:34:12 PM

Function value

A Function is a value which, when invoked with arguments, produces a new value. Functions are written by listing the function’s parameters in parentheses, followed by the goes-to symbol =>, followed by the expression defining the function. For example, to create a function called “MyFunction” that has two parameters and performs a calculation on parameter1 and parameter2:

This code produces the value of 3.

Structured data values

The M language supports the following structured data values:

Note

Structured data can contain any M value. To see a couple of examples, see Additional structured data examples.

List

A List is a zero-based ordered sequence of values enclosed in curly brace characters { }. The curly brace characters { } are also used to retrieve an item from a List by index position. See [List value](#_List_value).

Note

Power Query M supports an infinite list size, but if a list is written as a literal, the list has a fixed length. For example, {1, 2, 3} has a fixed length of 3.

The following are some List examples.

Value	Type
{123, true, 'A'}	List containing a number, a logical, and text.
{1, 2, 3}	List of numbers
{ {1, 2, 3}, {4, 5, 6} }	List of List of numbers
{ [CustomerID = 1, Name = 'Bob', Phone = '123-4567'], [CustomerID = 2, Name = 'Jim', Phone = '987-6543'] }	List of Records
{123, true, 'A'}{0}	Get the value of the first item in a List. This expression returns the value 123.
{ {1, 2, 3}, {4, 5, 6} }{0}{1}	Get the value of the second item from the first List element. This expression returns the value 2.

Record

A Record is a set of fields. A field is a name/value pair where the name is a text value that is unique within the field’s record. The syntax for record values allows the names to be written without quotes, a form also referred to as identifiers. An identifier can take the following two forms:

identifier_name such as OrderID.
#'identifier name' such as #'Today's data is: '.

The following is a record containing fields named 'OrderID', 'CustomerID', 'Item', and 'Price' with values 1, 1, 'Fishing rod', and 100.00. Square brace characters [ ] denote the beginning and end of a record expression, and are used to get a field value from a record. The follow examples show a record and how to get the Item field value.

Here's an example record:

To get the value of an Item, you use square brackets as Source[Item]:

Table

A Table is a set of values organized into named columns and rows. The column type can be implicit or explicit. You can use #table to create a list of column names and list of rows. A Table of values is a List in a List. The curly brace characters { } are also used to retrieve a row from a Table by index position (see Example 3 – Get a row from a table by index position).

Example 1 - Create a table with implicit column types

Example 2 – Create a table with explicit column types

Both of the examples above creates a table with the following shape:

OrderID	CustomerID	Item	Price
1	1	Fishing rod	100.00
2	1	1 lb. worms	5.00

Example 3 – Get a row from a table by index position

This expression returns the follow record:

OrderID	2
CustomerID	1
Item	1 lb. worms
Price	5

Additional structured data examples

Structured data can contain any M value. Here are some examples:

Example 1 - List with [Primitive](#_Primitive_value_1) values, [Function](#_Function_value), and [Record](#_Record_value)

Evaluating this expression can be visualized as:

Example 2 - Record containing Primitive values and nested Records

Evaluating this expression can be visualized as:

Note

Although many values can be written literally as an expression, a value is not an expression. For example, the expression 1 evaluates to the value 1; the expression 1+1 evaluates to the value 2. This distinction is subtle, but important. Expressions are recipes for evaluation; values are the results of evaluation.

If expression

The if expression selects between two expressions based on a logical condition. For example:

The first expression (2 + 2) is selected if the logical expression (2 > 1) is true, and the second expression (1 + 1) is selected if it is false. The selected expression (in this case 2 + 2) is evaluated and becomes the result of the if expression (4).

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Quantifiers specify how many instances of a character, group, or character class must be present in the input for a match to be found. The following table lists the quantifiers supported by .NET.

Greedy quantifier	Lazy quantifier	Description
`*`	`*?`	Match zero or more times.
`+`	`+?`	Match one or more times.
`?`	`??`	Match zero or one time.
`{`n`}`	`{`n`}?`	Match exactly n times.
`{`n`,}`	`{`n`,}?`	Match at least n times.
`{`n`,`m`}`	`{`n`,`m`}?`

Expressions 1.1