ISLOGICAL in Collabora Office: Check Boolean Values Without Confusing False with Failure

• Introduced: original Collabora release and launch date are not established by the sources reviewed.
• Availability: documented in Collabora Office 26.04 help, scoped to the desktop-help release.
• Platform scope: support in every online or mobile deployment is not inferred from desktop documentation.
• Checked: October 14, 2026. Function-specific documentation and independently derived controls; no native Collabora test was performed.

=ISLOGICAL(value)

value is the value or expression to test. The official Collabora section defines logical TRUE and FALSE as qualifying values, and states that an error returns FALSE from ISLOGICAL.

There are two different questions: “Is this a logical value?” and “Is this logical value true?” ISLOGICAL answers the first. Keep that distinction explicit in labels and reports so a valid FALSE flag is not misclassified as malformed data.

Prepare the following cells:

In B2 enter =ISLOGICAL(A2) and fill down. Expected flags are TRUE, TRUE, FALSE, FALSE, FALSE, FALSE.

The quoted strings spell familiar logical words but remain text. Formula-generated text makes the distinction reproducible without relying on how an application parses manually typed TRUE in a particular locale.

=ISLOGICAL(5>3)
=ISLOGICAL(5<3)
=ISLOGICAL(5=5)

Expected results: TRUE, TRUE and TRUE. The underlying comparisons return TRUE, FALSE and TRUE respectively, but all three results are logical values.

This is useful when a helper column should contain comparisons. ISLOGICAL can check the output type while a separate rule decides whether the actual comparison result permits a later step.

For A2:A7, enter in C2 and fill down:

=IF(ISLOGICAL(A2);"Logical flag";"Review type")

Expected labels are Logical flag, Logical flag, Review type, Review type, Review type, Review type.

To inspect the value of a confirmed logical flag, use a second scalar conditional:

=IF(ISLOGICAL(A2);IF(A2;"Enabled";"Disabled");"Review type")

Expected labels are Enabled, Disabled, Review type, Review type, Review type, Review type. This is an ordinary scalar control, not a general guarantee about every array-evaluation context. Preserve the source values so the labels do not conceal why a row required review.

The Collabora reference specifically uses ISNA inside ISLOGICAL. Try:

=ISLOGICAL(ISNA(NA()))
=ISLOGICAL(ISNA(8))

Expected results: TRUE and TRUE. The inner ISNA results differ, but both are logical. ISNA identifies the unavailable-value error class; its result type is independently useful to check when composing a diagnostic formula.

This does not mean the original NA() input is logical. =ISLOGICAL(NA()) is expected to return FALSE. The outer function is examining whichever value the inner expression actually returns.

Map B2:B7 to numeric indicators in an unused column:

=IF(B2;1;0)

Expected indicators are 1, 1, 0, 0, 0, 0, totaling 2. That is a count of logical entries, not a count of enabled entries. Among the controlled valid logical values, one is enabled and one is disabled.

Explicit numeric mapping avoids assuming how a different aggregate handles Boolean values in a range. Keep the source and flag ranges aligned and exclude headers from a data-only count.

An imported numeric code or text label may represent a Boolean concept in the source system without already being a logical value in the worksheet. Define the mapping deliberately rather than changing types until the screen looks right.

This guide uses explicit logical formulas, a documented numeric control, quoted words and a documented error case. Genuinely empty references, unusual numeric formatting and every import-coercion path remain outside the native evidence. The examples were independently checked, not run in Collabora.

• Collabora Office 26.04: ISLOGICAL.
• Editorial testing standards.

The direct product reference establishes the function definition and stated type/error distinctions. Worked controls were independently checked; native execution and broader client compatibility remain unverified.