JavaScript Arithmetik
JavaScript -Arithmetikoperatoren
Arithmetische Operatoren führen Arithmetik für Zahlen (Literale oder Variablen) durch.
| Operator | Beschreibung |
|---|---|
| + | Zusatz |
| - | Subtraktion |
| * | Multiplikation |
| ** | Exponentiation (ES2016) |
| / | Division |
| % | Modul (Rest) |
| ++ | Inkrement |
| -- | Dekrementieren |
Arithmetische Operationen
Ein typischer arithmetischer Betrieb arbeitet auf zwei Zahlen.
Die beiden Zahlen können Literale sein:
oder Variablen:
oder Ausdrücke:
Operatoren und Operanden
Die Zahlen (in einer arithmetischen Operation) werden Operanden genannt.
Die Operation (die zwischen den beiden Operanden ausgeführt werden soll) wird durch einen Operator definiert.
| Operand | Operator | Operand |
|---|---|---|
| 100 | + | 50 |
Adding
The addition operator (+) adds numbers:
Subtracting
The subtraction operator (-) subtracts numbers.
Multiplying
The multiplication operator (*) multiplies numbers.
Dividing
The division operator (/) divides numbers.
Remainder
The modulus operator (%) returns the division remainder.
In arithmetic, the division of two integers produces a quotient and a remainder.
In mathematics, the result of a modulo operation is the remainder of an arithmetic division.
Incrementing
The increment operator (++) increments numbers.
Decrementing
The decrement operator (--) decrements numbers.
Exponentiation
The exponentiation operator (**) raises the first operand to the power of the second operand.
x ** y produces the same result as Math.pow(x,y):
Operator Precedence
Operator precedence describes the order in which operations are performed in an arithmetic expression.
Is the result of example above the same as 150 * 3, or is it the same as 100 + 150?
Is the addition or the multiplication done first?
As in traditional school mathematics, the multiplication is done first.
Multiplication (*) and division (/) have higher precedence than addition (+) and subtraction (-).
And (as in school mathematics) the precedence can be changed by using parentheses:
When using parentheses, the operations inside the parentheses are computed first.
When many operations have the same precedence (like addition and subtraction), they are computed from left to right:
JavaScript Operator Precedence Values
Pale red entries indicate ECMAScript 2015 (ES6) or higher.
| Value | Operator | Description | Beispiel |
|---|---|---|---|
| 21 | ( ) | Expression grouping | (3 + 4) |
| 20 | . | Member | person.name |
| 20 | [] | Member | person["name"] |
| 20 | () | Function call | myFunction() |
| 20 | new | Create | new Date() |
| 18 | ++ | Postfix Increment | i++ |
| 18 | -- | Postfix Decrement | i-- |
| 17 | ++ | Prefix Increment | ++i |
| 17 | -- | Prefix Decrement | --i |
| 17 | ! | Logical not | !(x==y) |
| 17 | typeof | Type | typeof x |
| 16 | ** | Exponentiation (ES2016) | 10 ** 2 |
| 15 | * | Multiplication | 10 * 5 |
| 15 | / | Division | 10 / 5 |
| 15 | % | Division Remainder | 10 % 5 |
| 14 | + | Addition | 10 + 5 |
| 14 | - | Subtraction | 10 - 5 |
| 13 | << | Shift left | x << 2 |
| 13 | >> | Shift right | x >> 2 |
| 13 | >>> | Shift right (unsigned) | x >>> 2 |
| 12 | < | Less than | x < y |
| 12 | <= | Less than or equal | x <= y |
| 12 | > | Greater than | x > y |
| 12 | >= | Greater than or equal | x >= y |
| 12 | in | Property in Object | "PI" in Math |
| 12 | instanceof | Instance of Object | instanceof Array |
| 11 | == | Equal | x == y |
| 11 | === | Strict equal | x === y |
| 11 | != | Unequal | x != y |
| 11 | !== | Strict unequal | x !== y |
| 10 | & | Bitwise AND | x & y |
| 9 | ^ | Bitwise XOR | x ^ y |
| 8 | | | Bitwise OR | x | y |
| 7 | && | Logical AND | x && y |
| 6 | || | Logical OR | x || y |
| 5 | ?? | Nullish Coalescing | x ?? y |
| 4 | ? : | Condition | ? "Yes" : "No" |
| 3 | += | Assignment | x += y |
| 3 | /= | Assignment | x /= y |
| 3 | -= | Assignment | x -= y |
| 3 | *= | Assignment | x *= y |
| 3 | %= | Assignment | x %= y |
| 3 | <<= | Assignment | x <<= y |
| 3 | >>= | Assignment | x >>= y |
| 3 | >>>= | Assignment | x >>>= y |
| 3 | &= | Assignment | x &= y |
| 3 | ^= | Assignment | x ^= y |
| 3 | |= | Assignment | x |= y |
| 2 | yield | Pause Function | yield x |
| 1 | , | Comma | 5 , 6 |
Ausdrücke in Klammern werden vollständig berechnet, bevor der Wert im Rest des Ausdrucks verwendet wird.
