Latin Capital Letter E
Derived from the most frequently used letter in English, uppercase 'E' carries that statistical weight into every capitalized word and sentence opening. It sits at ASCII code point 69 (0x45), exactly 32 below its lowercase counterpart 'e' at 101 (0x65), maintaining the single-bit case offset (bit 5) shared by all ASCII A–Z / a–z pairs. It also functions as one of the six hexadecimal letter-digits, representing the value 14.
Technical Details
Code Example
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// Scientific notation in Cdouble large = 1.5E6; // 1,500,000double small = 2.5E-3; // 0.0025
Common Usage
Hexadecimal digit: Uppercase 'E' represents 14 in hex and appears throughout byte values like 0xEF and 0xFE. It is the default form in many hex-dump utilities, and C-family printf-style formatting with %X produces uppercase hex output including 'E'.
Scientific notation conventions: While most programming languages use lowercase 'e' in floating-point literals (1.5e3), several output formats and engineering tools prefer uppercase 'E' to avoid ambiguity with the mathematical constant e. Fortran historically used both, and IEEE 754 documentation typically shows the uppercase form.
Frequency analysis anchor: Because 'E' descends from the most common English letter, its uppercase form is a frequent early target when applying frequency analysis to ciphertext that preserves case. Its dominance was documented as a cryptanalytic lever as early as al-Kindi's 9th-century treatise.
Diacritical variants: Uppercase 'E' supports an extensive set of accented forms — È, É, Ê, Ë, Ě, Ę, Ē — appearing across French, Spanish, Czech, Polish, Māori, and many other orthographies. In most languages these remain variants of the same letter, though their correct rendering is essential for proper nouns and sentence-initial positions.
Hexadecimal digit: Uppercase 'E' represents 14 in hex and appears throughout byte values like 0xEF and 0xFE. It is the default form in many hex-dump utilities, and C-family printf-style formatting with %X produces uppercase hex output including 'E'.
Scientific notation conventions: While most programming languages use lowercase 'e' in floating-point literals (1.5e3), several output formats and engineering tools prefer uppercase 'E' to avoid ambiguity with the mathematical constant e. Fortran historically used both, and IEEE 754 documentation typically shows the uppercase form.
Frequency analysis anchor: Because 'E' descends from the most common English letter, its uppercase form is a frequent early target when applying frequency analysis to ciphertext that preserves case. Its dominance was documented as a cryptanalytic lever as early as al-Kindi's 9th-century treatise.
Diacritical variants: Uppercase 'E' supports an extensive set of accented forms — È, É, Ê, Ë, Ě, Ę, Ē — appearing across French, Spanish, Czech, Polish, Māori, and many other orthographies. In most languages these remain variants of the same letter, though their correct rendering is essential for proper nouns and sentence-initial positions.