Not-Equal Sign vs Slash-Equal

The not-equal-to sign (≠, U+2260) is a single Unicode mathematical operator representing inequality (x ≠ y), while != is a two-character ASCII sequence used as the inequality operator in most programming languages including Python, JavaScript, C, and Java. In mathematical and scientific typesetting, U+2260 is always preferred because it is a proper single glyph with balanced visual weight, whereas != is a pragmatic ASCII fallback for keyboards that lack a dedicated key for the symbol. Some programming languages do accept the Unicode operator directly — for example, Python 3 allows ≠ in certain Unicode identifier contexts, and some functional languages use it natively — but this is far from universal and reduces portability. A related character is the almost-equal-to sign (≈, U+2248), used for approximations, and the strictly-not-equal sign (≢, U+2262), which has a slightly different logical meaning in formal mathematics. In HTML, the not-equal sign can be encoded as ≠ or ≠, making it accessible without needing special keyboard input.