Template:Valid

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Purpose

Determines whether something is valid in a certain context. Currently only implemented for determining if a number is within the precision that Wikipedia expressions can handle.

Returns

true if the argument is valid, false if it is not.

Examples

{{valid|number=A}} = false (not a number)

{{valid|number=1234}} = true

{{valid|number=+1234}} = true

{{valid|number=-1234}} = true

{{valid|number=(1234)}} = true (one pair of parenthesis is allowed)

{{valid|number=--1234}} = false (incorrect sign use)

{{valid|number=1234567890}} = true

{{valid|number=12345678901234567890}} = false (too large)

{{valid|number=1.234567890}} = true

{{valid|number=1.2345678901234567890}} = false (too many decimals)

Performance impact

Template:Valid returns "true" for a valid, single number (2+2 gives "false"), and allows scientific notation (such as: -3.45E-07). The precision limit is determined live, for whichever server is formatting the page, typically allowing 14-digit precision (plus trailing zeroes), but it does not detect extreme precision problems dropping minor end-digits:

• cannot reject: -10020030040050000000000000000.70, treated as -1.002003004005E+28

The template has been written with minimal markup text, and could be used 50,000-13,000 times per page, or less when all 30-digit numbers. Template:Valid is typically used at upper levels of other templates, so it is unlikely to trigger expansion-depth problems. However, it has an expansion-depth of 8 levels, and returns "false" if used when nested too deep inside other templates, such as at level 33 when the expansion depth limit is 40.

The above documentation is transcluded from Template:Valid/doc. (edit | history)
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