{ "category": "Information functions", "display_name": "ISLOGICAL", "entry_kind": "built_in_function", "eval_api": { "method": "POST", "url": "https://handbook.dnacalc.com/api/eval" }, "function_id": "FUNC.ISLOGICAL", "implementation_state": { "answer_bank": { "excel_builds": [ "20430" ], "larger_numeric": 0, "last_bit": 0, "matched": 1227, "other_mismatch": 0, "refused": 0, "rows": 1227, "unread": 0, "worst_ulp": 0 }, "detail": "Recorded: 1,227 in the answer bank and 11 workbook cells.", "dnacalc_commit": "9e1884369a678158dd82d3d74188daf986995e87", "in_catalogue": true, "state": "matches", "state_label": "Matches every recorded Excel answer", "summary": "Matches all 1,238 recorded answers", "workbook_corpus": { "cells": 11, "matched": 11 } }, "implementations": [ { "commit": "9e1884369a678158dd82d3d74188daf986995e87", "flavour": "excel-compatibility-candidate", "language": "Rust", "name": "CalcFunc", "own_code": [ "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/information.rs#L99-L99", "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/information.rs#L230-L238" ], "repository": "https://github.com/DnaCalc/DnaCalc", "shared_code": [ "catalogue/aggregate::reader", "catalogue/aggregate::read_reference", "catalogue/information::unary", "catalogue/information::scalar", "catalogue/information::known", "catalogue/information::predicate", "catalogue/information::each", "catalogue/information::n", "catalogue/information::n_of", "catalogue/information::referenced" ], "source": "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/information.rs#L99-L99", "state": "matches", "suite": null, "summary": "Matches all 1,238 recorded answers" } ], "json_url": "https://handbook.dnacalc.com/api/functions/FUNC.ISLOGICAL.json", "name": "ISLOGICAL", "notes": [], "schema": "efh.function-reference/v1", "section_order": [ "what-it-does", "try-it", "quirks", "how-to-implement", "version-differences", "alternatives" ], "sections": { "alternatives": "\n### Relationships\n\n\n- **`TYPE`** returns `4` for exactly the values `ISLOGICAL` calls `TRUE`. `4` is the odd number\n out in the `TYPE` code table — 1, 2, 4, 16, 64 — and the gap at 8 is a reminder that these are\n bit flags by origin.\n- **`ISNUMBER`** is the predicate people reach for when they want \"is it 1 or 0 or TRUE or\n FALSE?\" and it will not give them that; `ISNUMBER(TRUE)` is `FALSE` and `ISLOGICAL(1)` is\n `FALSE`, so neither predicate alone covers the union. `OR(ISNUMBER(x), ISLOGICAL(x))` does.\n- **`N`** converts a logical to 1 or 0 — the conversion `ISLOGICAL` declines to perform. `N` is\n the standard way to turn a `Logical` mask into a summable numeric mask, as is the double unary\n `--`.\n- **`TRUE()` and `FALSE()`** manufacture the values this predicate tests for.\n- **`ISNONTEXT`** is `TRUE` for logicals too, but for six other kinds as well; `ISLOGICAL` is the\n precise test.\n\n\n", "how-to-implement": "\n### Notes for implementers\n\n\n1. **Model `Logical` as its own kind.** An engine that represents booleans as numbers 1 and 0\n cannot implement `ISLOGICAL` at all, and cannot implement `TYPE` either. This is the single\n design decision the function polices.\n2. **Do not accept `\"TRUE\"`/`\"FALSE\"` text.** The to-logical primitive's text acceptance is\n per-family policy elsewhere; it must not leak into a kind test.\n3. **`ISLOGICAL(FALSE)` must be `TRUE`.** Worth an explicit test, because a naive \"is it truthy?\"\n shortcut passes every other case.\n4. **The kind must survive comparison operators.** `1=1` has to produce a `Logical`, not a\n number, or `ISLOGICAL` will report `FALSE` on the most natural way of producing a boolean.\n\n\n", "quirks": "\n### Result and edge cases\n\n\nReturns a `Logical`, or an array of `Logical` when the argument is an array.\n\n- **`FALSE` is a logical.** `ISLOGICAL(FALSE)` is `TRUE`. The predicate is about the kind, not\n the truth value, and an implementation that special-cases falsiness will get this wrong.\n- **`0` and `1` are `FALSE`.** Numbers, whatever their value.\n- **The strings `\"TRUE\"` and `\"FALSE\"` are `FALSE`.** They are `Text`.\n- **`Empty` is `FALSE`.** A blank cell is not a logical, even though most boolean contexts treat\n it as `FALSE`.\n- **`Error` is `FALSE` and does not propagate**; `ISLOGICAL` is one of the declared per-family\n exceptions to the propagation discipline in\n [coercion and lifting](../model/02-coercion-and-lifting.md).\n- **Logicals in scanned ranges are ignored by some aggregates** even though they are present as\n values. That is a scan-policy fact about `SUM` and friends, not about `ISLOGICAL`, but it is\n the same underlying kind distinction seen from the other side, and it is why a column of\n `TRUE`/`FALSE` can be simultaneously \"logical\" to `ISLOGICAL` and invisible to `SUM`.\n- **Arrays** are classified elementwise into a same-shaped mask.\n\n\n\n### Errors\n\nMicrosoft's IS-functions page documents no error return for `ISLOGICAL`.\n\n\n", "sources": "- Microsoft, \"IS functions\" —\n .\n Read for this page: the `ISLOGICAL` row and the non-conversion remark.\n- Microsoft, \"TYPE function\" —\n .\n Read for the code table, which assigns 4 to a logical value.\n- Handbook, [coercion and lifting](../model/02-coercion-and-lifting.md) — the to-logical\n primitive, its per-family text acceptance, and the range-scan treatment of logicals.\n\n\n", "version-differences": "The recorded environments below distinguish a reading from a same-input comparison. Counts describe captured inputs in each environment; overlapping captures and comparisons are not totals of unique worksheet calls.\n\n| Excel 16.0 build | Platform and CPU | Captured inputs |\n|---|---|---:|\n| 20430 | Windows, 64-bit, CPU not recorded | 1,227 |\n\nThe record contains no same-input comparison between these environments. Reading different inputs on different builds does not establish either a version change or cross-build agreement.\n\n[Recorded environments and comparison details](https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.ISLOGICAL.json).", "what-it-does": "\n`ISLOGICAL(value)` returns `TRUE` when the value it receives has kind `Logical` — that is, when\nit is the boolean `TRUE` or the boolean `FALSE` — and `FALSE` for every other kind.\n\nMicrosoft's condition: \"Value refers to a logical value.\"\n\n`Logical` is a **distinct kind**, not a number\n([the value universe](../model/01-value-universe.md)).\nIt converts to 1 or 0 on demand in arithmetic contexts, which is why `TRUE+0` is `1` and\n`SUM(TRUE)` is `1`, but the conversion is a coercion performed by the consuming function, not a\nproperty of the value. `ISLOGICAL` classifies before any of that happens, so:\n\n- `ISLOGICAL(TRUE)` is `TRUE`\n- `ISLOGICAL(1)` is `FALSE`\n- `ISLOGICAL(\"TRUE\")` is `FALSE` — the string, not the boolean\n- `ISLOGICAL(1=1)` is `TRUE` — comparison operators produce `Logical` values\n\nThe last line is the useful one: `ISLOGICAL` is the way to confirm that a comparison, a\n`NOT`/`AND`/`OR` result, or an `ISxxx` result really is a boolean and not a number that\nhappens to be 1 or 0.\n\n\n\n### Arguments\n\n\n`value` — required, exactly one.\n\nNot converted. Microsoft's remark: \"The value arguments of the IS functions are not converted.\"\nThe to-logical primitive described in\n[coercion and lifting](../model/02-coercion-and-lifting.md) — under which zero becomes `FALSE`,\nnonzero becomes `TRUE`, and in some contexts the strings `\"TRUE\"`/`\"FALSE\"` are accepted — is\nexactly what `ISLOGICAL` does not do. Whether text that names a logical is accepted at all is\nper-family policy elsewhere in Excel; here it is settled, because no conversion is attempted.\n\n" }, "signature": { "display": "ISLOGICAL(value)", "parameters": [ { "description": null, "name": "value", "optional": false, "repeats": false } ], "trailing_repeats": false }, "sources": { "metadata": { "admission": { "label": "implemented", "reason": null }, "arity": { "max": 1, "min": 1 }, "category": "Information functions", "classification": { "arg_preparation_profile": "ValuesOnlyPreAdapter", "coercion_lift_profile": "None", "determinism_class": "Deterministic", "error_collapse_profile": "None", "fec_dependency_profile": "None", "host_interaction_class": "None", "kernel_signature_class": "Custom", "rich_value_usage": "RichBlind", "surface_fec_dependency_profile": "RefOnly", "thread_safety_class": "SafePure", "volatility_class": "NonVolatile" }, "descriptions": { "long": null, "short": "TRUE when the value is TRUE or FALSE", "short_source": "dna-calc-own" }, "docs": { "english_description": "Returns TRUE if the value is a logical value", "microsoft_url": "https://support.microsoft.com/en-us/office/is-functions-0f2d7971-6019-40a0-a171-f2d869135665" }, "entry_kind": "built_in_function", "localized_family_names": [ { "locale": "ar-SA", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "bg-BG", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "cs-CZ", "names": [ "ISODD", "JE.CHYBA", "JE.CHYBHODN", "JE.ČISLO", "JE.LOGHODN", "JE.NEDEF", "JE.NETEXT", "JE.ODKAZ", "JE.PRÁZDNÉ", "JE.TEXT" ] }, { "locale": "da-DK", "names": [ "ER.FEJL", "ER.FJL", "ER.IKKE.TEKST", "ER.IKKE.TILGÆNGELIG", "ER.LOGISK", "ER.REFERENCE", "ER.TAL", "ER.TEKST", "ER.TOM", "ER.ULIGE" ] }, { "locale": "de-DE", "names": [ "ISODD", "ISTBEZUG", "ISTFEHL", "ISTFEHLER", "ISTKTEXT", "ISTLEER", "ISTLOG", "ISTNV", "ISTTEXT", "ISTZAHL" ] }, { "locale": "el-GR", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "en-AU", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "en-GB", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "en-US", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "es-ES", "names": [ "ES.IMPAR", "ESBLANCO", "ESERR", "ESERROR", "ESLOGICO", "ESNOD", "ESNOTEXTO", "ESNUMERO", "ESREF", "ESTEXTO" ] }, { "locale": "et-EE", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "fi-FI", "names": [ "ONEI_TEKSTI", "ONLUKU", "ONPARITON", "ONPUUTTUU", "ONTEKSTI", "ONTOTUUS", "ONTYHJÄ", "ONVIITT", "ONVIRH", "ONVIRHE" ] }, { "locale": "fr-FR", "names": [ "EST.IMPAIR", "ESTERR", "ESTERREUR", "ESTLOGIQUE", "ESTNA", "ESTNONTEXTE", "ESTNUM", "ESTREF", "ESTTEXTE", "ESTVIDE" ] }, { "locale": "he-IL", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "hr-HR", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "hu-HU", "names": [ "HIBA.E", "HIBÁS", "HIVATKOZÁS", "LOGIKAI", "NEM.SZÖVEG", "NINCS", "PÁRATLANE", "SZÁM", "SZÖVEG.E", "ÜRES" ] }, { "locale": "id-ID", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "it-IT", "names": [ "ISODD", "VAL.ERR", "VAL.ERRORE", "VAL.LOGICO", "VAL.NON.DISP", "VAL.NON.TESTO", "VAL.NUMERO", "VAL.RIF", "VAL.TESTO", "VAL.VUOTO" ] }, { "locale": "ja-JP", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "ko-KR", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "lt-LT", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "lv-LV", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "nb-NO", "names": [ "ERF", "ERFEIL", "ERIKKETEKST", "ERIT", "ERLOGISK", "ERREF", "ERTALL", "ERTEKST", "ERTOM", "ISODD" ] }, { "locale": "nl-NL", "names": [ "IS.ONEVEN", "ISFOUT", "ISFOUT2", "ISGEENTEKST", "ISGETAL", "ISLEEG", "ISLOGISCH", "ISNB", "ISTEKST", "ISVERWIJZING" ] }, { "locale": "pl-PL", "names": [ "CZY.ADR", "CZY.BŁ", "CZY.BŁĄD", "CZY.BRAK", "CZY.LICZBA", "CZY.LOGICZNA", "CZY.NIE.TEKST", "CZY.NIEPARZYSTE", "CZY.PUSTA", "CZY.TEKST" ] }, { "locale": "pt-BR", "names": [ "É.NÃO.DISP", "É.NÃO.TEXTO", "ÉCÉL.VAZIA", "ÉERRO", "ÉERROS", "ÉLÓGICO", "ÉNÚMERO", "ÉREF", "ÉTEXTO", "ISODD" ] }, { "locale": "pt-PT", "names": [ "É.CÉL.VAZIA", "É.ERRO", "É.ERROS", "É.LÓGICO", "É.NÃO.DISP", "É.NÃO.TEXTO", "É.NÚM", "É.REF", "É.TEXTO", "ÉÍMPAR" ] }, { "locale": "ro-RO", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "ru-RU", "names": [ "ЕЛОГИЧ", "ЕНД", "ЕНЕТЕКСТ", "ЕНЕЧЁТ", "ЕОШ", "ЕОШИБКА", "ЕПУСТО", "ЕССЫЛКА", "ЕТЕКСТ", "ЕЧИСЛО" ] }, { "locale": "sk-SK", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "sl-SI", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "sr-Latn-RS", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "sv-SE", "names": [ "ÄREJTEXT", "ÄRF", "ÄRFEL", "ÄRLOGISK", "ÄRSAKNAD", "ÄRTAL", "ÄRTEXT", "ÄRTOM", "ÄRTOM", "ÄRUDDA" ] }, { "locale": "th-TH", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "tr-TR", "names": [ "EBOŞSA", "EHATA", "EHATALIYSA", "EMANTIKSALSA", "EMETİNDEĞİLSE", "EMETİNSE", "EREFSE", "ESAYIYSA", "EYOKSA", "TEKMİ işlevi" ] }, { "locale": "uk-UA", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "vi-VN", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "zh-CN", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "zh-HK", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] }, { "locale": "zh-TW", "names": [ "ISBLANK", "ISERR", "ISERROR", "ISLOGICAL", "ISNA", "ISNONTEXT", "ISNUMBER", "ISODD", "ISREF", "ISTEXT" ] } ], "localized_names": [], "signature": { "display": "ISLOGICAL(value)", "parameters": [ { "description": null, "name": "value", "optional": false, "repeats": false } ], "trailing_repeats": false }, "surface_name": "ISLOGICAL", "version_marker": null, "xlcall": { "code": "198", "symbol": "xlfIslogical" } }, "microsoft": "https://support.microsoft.com/en-us/office/is-functions-0f2d7971-6019-40a0-a171-f2d869135665" }, "try_it": { "formula": "=ISLOGICAL(1)" }, "url": "https://handbook.dnacalc.com/functions/ISLOGICAL.html", "variants": [], "versions": [ { "behaviour": "1,227 captured inputs are indexed for this environment. Capture dates: 2026-09-29 to 2026-09-29. This is a reading count, not a comparison with another build.", "excel_build": "16.0 build 20430", "platform": "Windows, 64-bit, CPU not recorded", "sources": [ "https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.ISLOGICAL.json" ] } ] }