These are the global objects that are set up automatically by the SpiderMonkey js command-line interpreter when you start the program.
Note: this list overlaps with "Built-in functions" in Introduction to the JavaScript shell and is probably not complete. See js/src/shell/js.cpp (around shell_functions) for more.
Global objects
- environment
- An object with a property for each environment variable
- arguments or scriptArgs in recent versions
- An array of command-line arguments (not including spidermonkey's flags)
- it
- ?
- File
- The deprecated File constructor, which requires a custom build flag to be enabled. See the File API documentation for details.
- PerfMeasurement
- See PerfMeasurement.jsm.
- Reflect
- The JavaScript parser API.
Functions
- version([number])
- Get or force a script compilation version number
- revertVersion()
- Revert previously set version number
- options([option, ...])
- Get or toggle JavaScript options
- load(['foo.js', ...])
- Load files named by string arguments
- evaluate(code)
- Evaluate code as though it were the contents of a file
- run('foo.js')
- Run the file named by the first argument, returning the number of milliseconds spent compiling and executing it
- readline()
- Read a single line from stdin
- print([exp, ...])
- Evaluate and print expressions
- putstr([exp])
- Evaluate and print expression without newline
- dateNow()
- Return the current time with sub-ms precision
- help([name, ...])
- Display usage and help messages
- quit()
- Quit the shell
- assertEq(actual, expected[, msg])
- Throw if the first two arguments are not the same (both +0 or both -0, both NaN, or non-zero and ===)
- gc()
- Run the garbage collector
- gcstats()
- Print garbage collector statistics
- gcparam(name, value)
- Wrapper for JS_SetGCParameter. The name must be either 'maxBytes' or 'maxMallocBytes' and the value must be convertable to a positive uint32
- countHeap([start[, kind]])
- Count the number of live GC things in the heap or things reachable from start when it is given and is not null. kind is either 'all' (default) to count all things or one of 'object', 'double', 'string', 'function', 'qname', 'namespace', 'xml' to count only things of that kind
- makeFinalizeObserver()
- Get a special object whose finalization increases the counter returned by the finalizeCount function
- finalizeCount()
- Return the current value of the finalization counter that is incremented each time an object returned by the makeFinalizeObserver is finalized
- gczeal(level)
- How zealous the garbage collector should be
- setDebug(debug)
- Set debug mode
- setDebuggerHandler(f)
- Set handler for
debuggerkeyword to f - line2pc([fun, ] line)
- Map line number to PC
- pc2line(fun[, pc])
- Map PC to line number
- stackQuota([number]) Obsolete since JavaScript 1.8.6
- Query/set script stack quota
- throwError()
- Throw an error from JS_ReportError
- dis([options, ...][fun])
- Disassemble functions into bytecodes. Recognized options:
"-r" (disassembled recursively)
"-l" (show line numbers) - disfile('foo.js')
- Disassemble script file into bytecodes. Recognized options:
"-r" (disassembled recursively)
"-l" (show line numbers) - dissrc([fun])
- Disassemble functions with source lines
- dumpHeap([fileName[, start[, toFind[, maxDepth[, toIgnore]]]]])
- Interface to JS_DumpHeap with output sent to file
- dumpObject()
- Dump an internal representation of an object
- notes([fun])
- Show source notes for functions
- stats([string, ...])
- Dump 'arena', 'atom', 'global' stats
- build()
- Show build date and time
- clear([obj])
- Clear properties of object
- intern(str)
- Internalize str in the atom table
- clone(fun[, scope])
- Clone function object
- getslx(obj)
- Get script line extent
- toint32(n)
- Testing hook for JS_ValueToInt32
- evalcx(s[, o])
- Evaluate s in optional sandbox object o.
if(s == '' && !o)return new o with eager standard classes
if(s == 'lazy' && !o)return new o with lazy standard classes
if(s == 'split' && !o)return new split-object o with lazy standard classes - evalInFrame(n, str, save)
- Evaluate 'str' in the nth up frame. If 'save' (default false), save the frame chain
- shapeOf(obj)
- Get the shape of obj (an implementation detail)
- arrayInfo(a1, a2, ...)
- Report statistics about arrays
- snarf(filename, [options])
- Read filename and return its contents as a string. If the second argument is the string "binary", the file will be returned as an Uint8Array instead of a string.
- read(filename)
- Synonym for snarf
- compile(code)
- Compiles a string to bytecode, potentially throwing
- parse(code)
- Parses a string, potentially throwing
- timeout([seconds])
- Get/Set the limit in seconds for the execution time for the current context. A negative value (default) means that the execution time is unlimited.
- elapsed()
- Execution time elapsed for the current context.
- serialize(sd)
- Serialize sd using JS_WriteStructuredClone. Returns a TypedArray.
- deserialize(a)
- Deserialize data generated by serialize.