| JavaScript Text Symbol |
Description | True Expression |
False Expression |
|---|---|---|---|
| && | and |
(x > 0 && x < y) (x * 2 == y + 4 && x + 1 == y) (y >= x && y / 2 > 1 && x > 0) |
(x > 0 && y < x) (x * 2 == y + 4 && x + 1 > y) (y >= x && y / 2 > 1 && x < 0) |
| ¦¦ | or |
(x > 0 ¦¦ y < x) (x > 0 ¦¦ x < y) (y >= x ¦¦ y / 2 < 1) (y < x ¦¦ y / 2 > 1 ¦¦ x < 0) |
(x < 0 ¦¦ y < x) (y < x ¦¦ y < 0) (y == x ¦¦ y / 2 < 1) (y < x ¦¦ y / 2 < 1 ¦¦ x < 0) |
| ! | not |
!(x > 0 && y < x) !(x * 2 == y + 4 && x + 1 > y) !(x < 0 ¦¦ y < x) !(y < x ¦¦ y < 0) |
!(x > 0 && x < y) !(x * 2 == y + 4 && x + 1 == y) !(x > 0 ¦¦ y < x) !(x > 0 ¦¦ x < y) |
| Order | Operator | Description & Comments | Example | Result |
|---|---|---|---|---|
| 1 | () | Parenthesis: Always do first, work from inside out | 1 * 2 + 3 * 4 + 5 1 * (2 + 3) * 4 + 5 1 * (2 + 3) * (4 + 5) |
19 25 45 |
| 2 | ! | Boolean not: reverses the true/false value | !(x < 6) (x >= 6) |
true for 6, 7, 8, 9... same |
| 3 | * / % | Multiply, divide, remainder | 2 * 3 + 4 2 * (3 % 4) 2 * (4 % 3) |
10 6 2 |
| 4 | + - | Add, concatenate, subtract | 2 + 3 "Jane" + " " + "Doe" "two" + 3 2 + 3 * 4 - 5 |
5 "Jane Doe" "two3" 9 |
| 5 | < <= > >= | Relational Comparisons | x + 1 > 5 x / 2 <= 3 |
true for 5, 6, 7, 8... true for 6, 5, 4, 3,... |
| 6 | == != | Equality & inequality | x != 3 x % 2 == 0 |
true for any x, except 3 true for any even number |
| 7 | && | Boolean and: all conditions must be true | (x % 2 == 0) && (x > 10) (x < 7) && x > 0 |
12, 14, 16, 18... 1, 2, 3, 4, 5, 6 |
| 8 | ¦¦ | Boolean or: any one (or more) condition may be true | (x % 2 == 0) ¦¦ (x < 0) (x < 0 ¦¦ x > 3) |
Number is even or negative Anything not between 0 and 3 |
| 9 | = | Assignment | y = 3 * 2 + 1 | 7 is saved in y |
All work herein is subject to copyright. Original content to Dr. Paul Mullins, text content (Head First HTML with CSS & XHTML) to O'Reilly publishing, other tools (such as Homesite HTML-Kit and FireFox) to their respective owners.