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$regexFindAll

Definition

Finds regex matches and their UTF-16 indexes.

Expression operator · Text · Studio Visual: available. Studio validates the complete expression separately.

Syntax

{
  "$regexFindAll": {
    "input": <input>,
    "regex": <regex>,
    "options": <options>
  }
}

Replace angle-bracket placeholders with expressions or values.

Optional parameters may be omitted.

Parameters

Parameter Required Description
input Yes Expression supplying the value to process. A field reference such as "$price" reads from the current document.
regex Yes Regular-expression pattern to search for.
options No Regex option string. See Supported values below.

Supported values

options accepts any combination of i (case-insensitive), m (multiline anchors), s (dot matches newlines), and x (ignore pattern whitespace/comments). Omit it or use "" for no flags. Patterns use Java regular-expression behavior.

Behavior

The following observations use the example expression below. Each row substitutes one argument while retaining the other example arguments. A missing field differs from an explicit null; the result shown is what Core actually returned.

For the input argument:

Input case Supplied value Result
null null Error — Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null
missing Field absent Error — Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null
decimal 2.5 Error — class java.lang.Double cannot be cast to class java.lang.String (java.lang.Double and java.lang.String are in module java.base of loader 'bootstrap')
numeric string "12" []
text "hello" []
boolean true Error — class java.lang.Boolean cannot be cast to class java.lang.String (java.lang.Boolean and java.lang.String are in module java.base of loader 'bootstrap')
typed date {"$date":"2026-01-15T15:00:00Z"} Error — class java.util.Date cannot be cast to class java.lang.String (java.util.Date and java.lang.String are in module java.base of loader 'bootstrap')
empty array [] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
numeric array [1,2,3] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
object {"x":1} Error — class org.bson.Document cannot be cast to class java.lang.String (org.bson.Document is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstr

Argument handling

Invocation Result
{"$regexFindAll":[]} Error — class java.util.ArrayList cannot be cast to class java.util.Map (java.util.ArrayList and java.util.Map are in module java.base of loader 'bootstrap')
{"$regexFindAll":{"unexpected":1}} Error — Cannot invoke "String.isEmpty()" because "this.pattern" is null

Examples

Expression: 

{
  "$regexFindAll": {
    "input": "abc",
    "regex": "ab"
  }
}

Input document: 

{}

Observed SrotaX result: [{"idx":0,"captures":[],"match":"ab"}].

Detailed input cases

Expand the complete argument-by-argument test matrix

Each table changes only the indicated argument from the example above. Other arguments retain their baseline values. Values normally come from the input field probe; literal configuration arguments are replaced directly. “Missing” means the field is absent, not explicitly null. Numeric strings are strings, not numbers.

Argument: input

Input case Supplied value SrotaX result
null null Error — Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null
missing Field absent Error — Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null
zero 0 Error — class java.lang.Integer cannot be cast to class java.lang.String (java.lang.Integer and java.lang.String are in module java.base of loader 'bootstrap')
negative -2 Error — class java.lang.Integer cannot be cast to class java.lang.String (java.lang.Integer and java.lang.String are in module java.base of loader 'bootstrap')
decimal 2.5 Error — class java.lang.Double cannot be cast to class java.lang.String (java.lang.Double and java.lang.String are in module java.base of loader 'bootstrap')
numeric string "12" []
text "hello" []
empty string "" []
boolean true Error — class java.lang.Boolean cannot be cast to class java.lang.String (java.lang.Boolean and java.lang.String are in module java.base of loader 'bootstrap')
false false Error — class java.lang.Boolean cannot be cast to class java.lang.String (java.lang.Boolean and java.lang.String are in module java.base of loader 'bootstrap')
typed date {"$date":"2026-01-15T15:00:00Z"} Error — class java.util.Date cannot be cast to class java.lang.String (java.util.Date and java.lang.String are in module java.base of loader 'bootstrap')
decimal128 {"$numberDecimal":"1.25"} Error — class org.bson.types.Decimal128 cannot be cast to class java.lang.String (org.bson.types.Decimal128 is in unnamed module of loader 'app'; java.lang.String is in module java.base of
empty array [] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
numeric array [1,2,3] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
mixed array [1,null,"x",3] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
nested array [[1,2],[3]] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
empty object {} Error — class org.bson.Document cannot be cast to class java.lang.String (org.bson.Document is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstr
object {"x":1} Error — class org.bson.Document cannot be cast to class java.lang.String (org.bson.Document is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstr
ISO date string "2026-01-15T15:00:00Z" []
omitted named argument Argument removed Error — Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null

Argument: regex

Input case Supplied value SrotaX result
null null Error — Cannot invoke "String.isEmpty()" because "this.pattern" is null
missing Field absent Error — Cannot invoke "String.isEmpty()" because "this.pattern" is null
zero 0 Error — class java.lang.Integer cannot be cast to class java.lang.String (java.lang.Integer and java.lang.String are in module java.base of loader 'bootstrap')
negative -2 Error — class java.lang.Integer cannot be cast to class java.lang.String (java.lang.Integer and java.lang.String are in module java.base of loader 'bootstrap')
decimal 2.5 Error — class java.lang.Double cannot be cast to class java.lang.String (java.lang.Double and java.lang.String are in module java.base of loader 'bootstrap')
numeric string "12" []
text "hello" []
empty string "" [{"idx":0,"captures":[],"match":""},{"idx":1,"captures":[],"match":""},{"idx":2,"captures":[],"match":""},{"idx":3,"captures":[],"match":""}]
boolean true Error — class java.lang.Boolean cannot be cast to class java.lang.String (java.lang.Boolean and java.lang.String are in module java.base of loader 'bootstrap')
false false Error — class java.lang.Boolean cannot be cast to class java.lang.String (java.lang.Boolean and java.lang.String are in module java.base of loader 'bootstrap')
typed date {"$date":"2026-01-15T15:00:00Z"} Error — class java.util.Date cannot be cast to class java.lang.String (java.util.Date and java.lang.String are in module java.base of loader 'bootstrap')
decimal128 {"$numberDecimal":"1.25"} Error — class org.bson.types.Decimal128 cannot be cast to class java.lang.String (org.bson.types.Decimal128 is in unnamed module of loader 'app'; java.lang.String is in module java.base of
empty array [] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
numeric array [1,2,3] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
mixed array [1,null,"x",3] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
nested array [[1,2],[3]] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
empty object {} Error — class org.bson.Document cannot be cast to class java.lang.String (org.bson.Document is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstr
object {"x":1} Error — class org.bson.Document cannot be cast to class java.lang.String (org.bson.Document is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstr
ISO date string "2026-01-15T15:00:00Z" []
omitted named argument Argument removed Error — Cannot invoke "String.isEmpty()" because "this.pattern" is null

Argument: options

Input case Supplied value SrotaX result
null null Error — Cannot invoke "String.matches(String)" because "options" is null
missing Field absent Error — Cannot invoke "String.matches(String)" because "options" is null
zero 0 Error — class java.lang.Integer cannot be cast to class java.lang.String (java.lang.Integer and java.lang.String are in module java.base of loader 'bootstrap')
negative -2 Error — class java.lang.Integer cannot be cast to class java.lang.String (java.lang.Integer and java.lang.String are in module java.base of loader 'bootstrap')
decimal 2.5 Error — class java.lang.Double cannot be cast to class java.lang.String (java.lang.Double and java.lang.String are in module java.base of loader 'bootstrap')
numeric string "12" Error — Unsupported regex option
text "hello" Error — Unsupported regex option
empty string "" [{"idx":0,"captures":[],"match":"ab"}]
boolean true Error — class java.lang.Boolean cannot be cast to class java.lang.String (java.lang.Boolean and java.lang.String are in module java.base of loader 'bootstrap')
false false Error — class java.lang.Boolean cannot be cast to class java.lang.String (java.lang.Boolean and java.lang.String are in module java.base of loader 'bootstrap')
typed date {"$date":"2026-01-15T15:00:00Z"} Error — class java.util.Date cannot be cast to class java.lang.String (java.util.Date and java.lang.String are in module java.base of loader 'bootstrap')
decimal128 {"$numberDecimal":"1.25"} Error — class org.bson.types.Decimal128 cannot be cast to class java.lang.String (org.bson.types.Decimal128 is in unnamed module of loader 'app'; java.lang.String is in module java.base of
empty array [] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
numeric array [1,2,3] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
mixed array [1,null,"x",3] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
nested array [[1,2],[3]] Error — class java.util.ArrayList cannot be cast to class java.lang.String (java.util.ArrayList and java.lang.String are in module java.base of loader 'bootstrap')
empty object {} Error — class org.bson.Document cannot be cast to class java.lang.String (org.bson.Document is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstr
object {"x":1} Error — class org.bson.Document cannot be cast to class java.lang.String (org.bson.Document is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstr
ISO date string "2026-01-15T15:00:00Z" Error — Unsupported regex option
omitted named argument Argument removed [{"idx":0,"captures":[],"match":"ab"}]

Verification

This page records 63 executed cases. It covers individual argument substitutions, not every cross-product of arguments, locale, daylight-saving transitions, numeric overflow, collation or resource limits. No untested behavior is guaranteed.

Download exact expressions, inputs and SrotaX results. Errors are observed messages, not stable public error codes. The reference generator reads the checked-in execution report; do not edit generated observations by hand.

MongoDB differences

Compared with MongoDB 9.0.4: 7 exact BSON matches, 46 both rejected, 7 value/type/acceptance differences, 3 object-field-order differences.

“Exact” includes numeric BSON types and object key order. A value of 3 as int32 differs from 3.0 as double. Object-field-order differences are reported separately; object key ordering is not enforced by the engine regression baseline. Both rejected does not mean the error codes or messages match. This is finite-case evidence, not full compatibility certification.

Show observed differences
Tested case SrotaX MongoDB
all / baseline [{"idx":0,"captures":[],"match":"ab"}] [{"match":"ab","idx":0,"captures":[]}]
input / null Error — Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null []
input / missing Error — Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null []
regex / null Error — Cannot invoke "String.isEmpty()" because "this.pattern" is null []
regex / missing Error — Cannot invoke "String.isEmpty()" because "this.pattern" is null []
regex / empty string [{"idx":0,"captures":[],"match":""},{"idx":1,"captures":[],"match":""},{"idx":2,"captures":[],"match":""},{"idx":3,"captures":[],"match":""}] [{"match":"","idx":0,"captures":[]},{"match":"","idx":1,"captures":[]},{"match":"","idx":2,"captures":[]}]
options / null Error — Cannot invoke "String.matches(String)" because "options" is null [{"match":"ab","idx":0,"captures":[]}]
options / missing Error — Cannot invoke "String.matches(String)" because "options" is null [{"match":"ab","idx":0,"captures":[]}]
options / empty string [{"idx":0,"captures":[],"match":"ab"}] [{"match":"ab","idx":0,"captures":[]}]
options / omitted named argument [{"idx":0,"captures":[],"match":"ab"}] [{"match":"ab","idx":0,"captures":[]}]

Download full comparison evidence.