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EnvHash

EnvHash() -> EnvHash

A singleton of this type provides a hash table interface to environment variables.

Examples

In the Julia programming language, the EnvHash() function returns a singleton EnvHash object that provides a hash table interface to environment variables.

julia> env = EnvHash()
EnvHash{String, String} with 0 entries

Common examples of its use:

1. Accessing environment variables:

   julia> env["HOME"]
   "/Users/username"

   This example retrieves the value of the "HOME" environment variable using the env object.

2. Modifying environment variables:

   julia> env["MY_VAR"] = "my_value"
   "my_value"

   It sets the value of the "MY_VAR" environment variable to "my_value" using the env object.

3. Iterating over environment variables:

   julia> for (key, value) in env
             println("$key = $value")
         end

   It iterates over all the key-value pairs in the env object and prints them.

Common mistake example:

julia> env = EnvHash()
EnvHash{String, String} with 0 entries

julia> env["MY_VAR"]
ERROR: KeyError: key "MY_VAR" not found

In this example, an attempt is made to access the value of an environment variable "MY_VAR" that does not exist. It's important to ensure that the environment variable you are trying to access actually exists.

See Also

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