However, in most languages where = has one of these meanings, a different character or, more often, a sequence of characters is used for the other meaning. [9], In Ruby, equality under == requires both operands to be of identical type, e.g. A set is a collection of things, usually numbers. Both usages have remained common in different programming languages into the early 21st century. We can list each element (or … If set A = {1,2,3,4,5} and set B = {5,4,3,2,1}, then both sets have the same number of elements as well as identical elements. In PHP, the triple equals sign, ===, denotes value and type equality,[8] meaning that not only do the two expressions evaluate to equal values, but they are also of the same data type. In chemical formulas, the two parallel lines denoting a double bond are commonly rendered using an equals sign. Additional symbols in Unicode related to the equals sign include:[19]. A few languages, such as BASIC and PL/I, have used the equals sign to mean both assignment and equality, distinguished by context. The equals sign was reserved for this usage. The symbol used to denote inequation (when items are not equal) is a slashed equals sign ≠ (U+2260). When we speak of equivalence of sets, we use the equivalent sign, which is the tilde (~) sign. [citation needed]. 0 == false is false. So if we wanted to say that set C was equivalent to set D, we would write: Set C ~ Set D. × Confusion between the two uses of the sign sometimes persists at the university level. But = is used for equality and not assignment in the Pascal family, Ada, Eiffel, APL, and other languages. The language B introduced the use of == with this meaning, which has been copied by its descendant C and most later languages where = means assignment. The = symbol, now universally accepted in mathematics for equality, was first recorded by Welsh mathematician Robert Recorde in The Whetstone of Witte (1557). If the condition discussed above is … This is represented by: A = B. The equals sign is also used as a grammatical tone letter in the orthographies of Budu in the Congo-Kinshasa, in Krumen, Mwan and Dan in the Ivory Coast. What are Equal Sets? [17], In Morse code, the equals sign is encoded by the letters B (-...) and T (-) run together (-...-). The expression 0 == false is true, but 0 == undefined is false, even though both sides of the == act the same in Boolean context. Symbol Symbol Name Meaning / definition Example; x: x variable: unknown value to find: when 2x = 4, then x = 2: equivalence: identical to ≜ equal by definition: equal by definition The etymology of the word "equal" is from the Latin word "æqualis", as meaning "uniform", "identical", or "equal", from aequus ("level", "even", or "just"). A possibly unique case of the equals sign of European usage in a person's name, specifically in a double-barreled name, was by pioneer aviator Alberto Santos-Dumont, as he is also known not only to have often used a double hyphen resembling an equals sign = between his two surnames in place of a hyphen, but also seems to have personally preferred that practice, to display equal respect for his father's French ethnicity and the Brazilian ethnicity of his mother.[15]. In mathematics, the equals sign can be used as a simple statement of fact in a specific case (x = 2), or to create definitions (let x = 2), conditional statements (if x = 2, then ...), or to express a universal equivalence ((x + 1)² = x² + 2x + 1). Contents. However, in JavaScript the behavior of == cannot be described by any simple consistent rules. In Unicode and ASCII, it has the code point 3D. [citation needed] The letters BT stand for Break Text, and are put between paragraphs, or groups of paragraphs in messages sent via Telex,[citation needed] a standardised tele-typewriter.