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deno eval

Evaluate JavaScript from the command line.

Command Jump to heading

deno eval [OPTIONS] <CODE_ARG>... - Executes code provided as a string argument.

Synopsis Jump to heading

deno eval [--no-check[=<NO_CHECK_TYPE]] [--import-map <FILE>] [-q|--quiet] [--no-remote] [--no-npm] 
[--node-modules-dir[=<node-modules-dir>]] [--vendor[=<vendor>]] [-c|--config <FILE>] [--no-config]
[-r|--reload[=<CACHE_BLOCKLIST>...]] [--lock [<FILE>]] [--lock-write] [--no-lock] [--cert <FILE>]
[--inspect[=<HOST_AND_PORT>]] [--inspect-brk[=<HOST_AND_PORT>]] [--inspect-wait[=<HOST_AND_PORT>]]
[--cached-only] [--location <HREF>] [--v8-flags[=<v8-flags>...]] [--seed <NUMBER>]
[--check[=<CHECK_TYPE>]] [--ext <EXT>] [-p|--print] [--env[=<FILE>]] <CODE_ARG>

deno eval -h|--help

Description Jump to heading

Evaluate JavaScript from the command line.

deno eval "console.log('hello world')"

To evaluate as TypeScript:

deno eval --ext=ts "const v: string = 'hello'; console.log(v)"

This command has implicit access to all permissions (--allow-all).

Arguments Jump to heading

CODE_ARG - A string-literal containing the JavaScript or TypeScript code to evaluate.

Options Jump to heading

  • --no-check[=<NO_CHECK_TYPE>]

    Skip type-checking. If the value of '--no-check=remote' is supplied, diagnostic errors from remote modules will be ignored.

  • --import-map <FILE>

    Load import map file from local file or remote URL. Docs: https://docs.deno.com/runtime/manual/basics/import_maps Specification: https://wicg.github.io/import-maps/ Examples: https://github.com/WICG/import-maps#the-import-map

  • -q, --quiet

    Suppress diagnostic output

  • --no-remote

    Do not resolve remote modules

  • --no-npm

    Do not resolve npm modules

  • --node-modules-dir[=<node-modules-dir>]

    Enables or disables the use of a local node_modules folder for npm packages

    [possible values: true, false]

  • --vendor[=<vendor>]

    UNSTABLE: Enables or disables the use of a local vendor folder for remote modules and node_modules folder for npm packages

    [possible values: true, false]

  • -c, --config <FILE>

    The configuration file can be used to configure different aspects of deno including TypeScript, linting, and code formatting. Typically the configuration file will be called deno.json or deno.jsonc and automatically detected; in that case this flag is not necessary. See https://deno.land/manual@v1.41.3/getting_started/configuration_file

  • --no-config

    Disable automatic loading of the configuration file

  • -r, --reload[=<CACHE_BLOCKLIST>...]

    Reload source code cache (recompile TypeScript).

    The CACHE_BLOCKLIST is a comma separated list of arguments passed to the --reload option.

    E.g. --reload=https://deno.land/std/fs/utils.ts,https://deno.land/std/fmt/colors.ts

  • --lock [<FILE>]

    Check the specified lock file. If value is not provided, defaults to "deno.lock" in the current working directory.

  • --lock-write

    Force overwriting the lock file

  • --no-lock

    Disable auto discovery of the lock file

  • --cert <FILE>

    Load the certificate from a PEM encoded file

  • --inspect[=<HOST_AND_PORT>]

    Activate inspector on host:port (default: 127.0.0.1:9229)

  • --inspect-brk[=<HOST_AND_PORT>]

    Activate inspector on host:port, wait for debugger to connect and break at the start of user script

  • --inspect-wait[=<HOST_AND_PORT>]

    Activate inspector on host:port and wait for debugger to connect before running user code

  • --cached-only

    Require that remote dependencies are already cached

  • --location <HREF>

    Value of 'globalThis.location' used by some web APIs

  • --v8-flags[=<v8-flags>...]

    To see a list of all available flags use --v8-flags=--help. Any flags set with this flag are appended after the DENO_V8_FLAGS environmental variable

  • --seed <NUMBER>

    Set the random number generator seed

  • --check[=<CHECK_TYPE>]

    Enable type-checking. This subcommand does not type-check by default. If the value of '--check=all' is supplied, diagnostic errors from remote modules will be included.

    Alternatively, the 'deno check' subcommand can be used.

  • --ext <EXT>

    Set content type of the supplied file

    [possible values: ts, tsx, js, jsx]

  • -p, --print

    print result to stdout

  • --env[=<FILE>]

    UNSTABLE: Load environment variables from local file. Only the first environment variable with a given key is used. Existing process environment variables are not overwritten.

  • -h, --help

    Print help (see a summary with '-h')

Examples Jump to heading

  • Execute JavaScript
deno eval "console.log('hello world')"
  • Execute TypeScript
deno eval --ext=ts "const v: string = 'hello'; console.log(v)"