Latin Capital Letter L
Sitting at ASCII code point 76 (0x4C), uppercase 'L' is exactly 32 below its lowercase counterpart 'l' at 108 (0x6C) — the standard single-bit case offset (bit 5) shared by all ASCII A–Z / a–z pairs. It is the 12th letter of the Latin alphabet and appears with moderate frequency in English, though its uppercase form gains extra visibility in abbreviations and proper nouns. In programming, 'L' carries a distinctive role as an integer literal suffix, making it one of the few letters with dedicated meaning outside identifier names.
Technical Details
Code Example
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// Long integer literal suffixlong big = 1000000L;long long bigger = 1000000000000LL;unsigned long flags = 0xFFFFFFFFUL;
Common Usage
Integer literal suffix: In C, C++, Java, and many other languages, appending 'L' (or lowercase 'l') to a numeric literal marks it as a long integer — e.g., 100L. Style guides overwhelmingly recommend the uppercase form because lowercase 'l' is easily confused with the digit '1' in most monospaced and proportional typefaces alike.
Typographic ambiguity: Uppercase 'L', lowercase 'l', and the digit '1' are notoriously similar in many sans-serif fonts such as Helvetica and Arial. This has driven coding-font design choices — typefaces like JetBrains Mono, Fira Code, and Source Code Pro add serifs or distinctive curves to disambiguate the three glyphs. The problem also motivates explicit bans on certain fonts in UI and signage standards.
Roman numeral and scientific notation: In Roman numerals, 'L' represents the value 50, appearing in combinations like XL (40) and LXX (70). In metrology, NIST and the international BIPM jointly recommend uppercase 'L' as the preferred symbol for liter — precisely because lowercase 'l' is too easily confused with the digit '1'. This makes 'L' one of the rare cases where a typographic ambiguity problem directly shaped an international scientific standard.
Diacritical variants: Uppercase 'L' is the base for several accented and modified forms — Ł (stroke) is a distinct letter in Polish and Sorbian, Ľ (caron) appears in Slovak, Ļ (cedilla) in Latvian, and Ḷ (dot below) in IAST transliteration of Sanskrit. Polish Ł represents a sound close to English /w/ and is sorted separately from plain L in the Polish alphabet.
Integer literal suffix: In C, C++, Java, and many other languages, appending 'L' (or lowercase 'l') to a numeric literal marks it as a long integer — e.g., 100L. Style guides overwhelmingly recommend the uppercase form because lowercase 'l' is easily confused with the digit '1' in most monospaced and proportional typefaces alike.
Typographic ambiguity: Uppercase 'L', lowercase 'l', and the digit '1' are notoriously similar in many sans-serif fonts such as Helvetica and Arial. This has driven coding-font design choices — typefaces like JetBrains Mono, Fira Code, and Source Code Pro add serifs or distinctive curves to disambiguate the three glyphs. The problem also motivates explicit bans on certain fonts in UI and signage standards.
Roman numeral and scientific notation: In Roman numerals, 'L' represents the value 50, appearing in combinations like XL (40) and LXX (70). In metrology, NIST and the international BIPM jointly recommend uppercase 'L' as the preferred symbol for liter — precisely because lowercase 'l' is too easily confused with the digit '1'. This makes 'L' one of the rare cases where a typographic ambiguity problem directly shaped an international scientific standard.
Diacritical variants: Uppercase 'L' is the base for several accented and modified forms — Ł (stroke) is a distinct letter in Polish and Sorbian, Ľ (caron) appears in Slovak, Ļ (cedilla) in Latvian, and Ḷ (dot below) in IAST transliteration of Sanskrit. Polish Ł represents a sound close to English /w/ and is sorted separately from plain L in the Polish alphabet.