# _murex_ Shell Docs

## Command Reference: `expr`

> Expressions: mathematical, string comparisons, logical operators

## Description



## Usage

    expr: expression -> <stdout>

## Examples

Order of operations:

    » 3 * (3 + 1)                                                                                                                                                                                                                         
    12
    
JSON array:

    » %[apples oranges grapes]
    [
        "apples",
        "oranges",
        "grapes"
    ]

## See Also

* [`=` (arithmetic evaluation)](../commands/equ.md):
  Evaluate a mathematical function (deprecated)
* [`let`](../commands/let.md):
  Evaluate a mathematical function and assign to variable (deprecated)
* [`set`](../commands/set.md):
  Define a local variable and set it's value