operators

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 3 years ago . In my code, I'm trying to make a not less than operator. I can't do a !< b ... what can I do? Is there any package / method I can use? 回答1: The opposite of a<b is a>=b , not a>b . EDIT: The syntax you were looking for is !(a<b) 回答2: Oh, I am so stupid! I could just do a >= b ! 来源：

问题 I am having a hard time understanding some code that shows an example how a double in Java could be transformed into a byte[] and vice versa. Here is the code being used to transform a double into a byte[]: public static byte [] doubleToByteArray (double numDouble) { byte [] arrayByte = new byte [8]; long numLong; // Takes the double and sticks it into a long, without changing it numLong = Double.doubleToRawLongBits(numDouble); // Then we need to isolate each byte // The casting of byte (byte

问题 I am having a hard time understanding some code that shows an example how a double in Java could be transformed into a byte[] and vice versa. Here is the code being used to transform a double into a byte[]: public static byte [] doubleToByteArray (double numDouble) { byte [] arrayByte = new byte [8]; long numLong; // Takes the double and sticks it into a long, without changing it numLong = Double.doubleToRawLongBits(numDouble); // Then we need to isolate each byte // The casting of byte (byte

问题 Looking at the list of bitwise operators in the Rust Book, I don't see a NOT operator (like ~ in C). Is there no NOT operator in Rust? 回答1: The ! operator is implemented for many primitive types and it's equivalent to the ~ operator in C. See this example (playground): let x = 0b10101010u8; let y = !x; println!("x: {:0>8b}", x); println!("y: {:0>8b}", y); Outputs: x: 10101010 y: 01010101 See also: How do you set, clear and toggle a single bit in Rust? 来源： https://stackoverflow.com/questions

问题 I have the following code for a simple calculator. The code works fine, but I want the value in the dropdown list to stay there after submitted. How would I do this? Essentially, I want the operator to stay selected once the calculation has been done. At the moment, it just shows a '+', even if the sum is 25 / 5. <?php $number1 = $_POST['number1']; $number2 = $_POST['number2']; $operation = $_POST['operator']; Switch ($operation) { case 'add': $answer = $number1 + $number2; break; case 'minus

问题 We can implement the traits in core::ops to define the behavior of operators for our types. The traits themselves are annotated with #[lang =...] attributes so the compiler knows which traits and operators belong together. For example, the Add implementation for primitive types looks like this (macro manually expanded and simplified from here): impl Add for i32 { type Output = i32; fn add(self, other: i32) -> i32 { self + other } } To my surprise, the implementation uses the + operator

问题 This question already has answers here : Is there a “null coalescing” operator in JavaScript? (13 answers) Closed 2 years ago . I just saw this syntax in PHP: // Fetches the value of $_GET['user'] and returns 'nobody' // if it does not exist. $username = $_GET['user'] ?? 'nobody'; Why don't we have the same in JavaScript? I am tired of doing: var name = obj['name'] ? obj['name'] : 'GOD'; 回答1: The Null coalescing operator is a recent addition to PHP. It was introduced in PHP 7 (released in

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: javascript >>> operator? JavaScript triple greater than Found this operator in such line of code: var t = Object(this), len = t.length >>> 0; What does this operator mean? Full code is below. It is the code of JS some method: if (!Array.prototype.some) { Array.prototype.some = function(fun /*, thisp */) { "use strict"; if (this == null) throw new TypeError(); var t = Object(this), len = t.length >>> 0; if

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: javascript >>> operator? JavaScript triple greater than Found this operator in such line of code: var t = Object(this), len = t.length >>> 0; What does this operator mean? Full code is below. It is the code of JS some method: if (!Array.prototype.some) { Array.prototype.some = function(fun /*, thisp */) { "use strict"; if (this == null) throw new TypeError(); var t = Object(this), len = t.length >>> 0; if

问题 This question already has answers here : Unexpected result with `in` operator chaining (1 answer) Chaining “is” operators (4 answers) Closed 2 months ago . Why is ('a' in arr) in arr != 'a' in arr in arr ? arr = [1, True, 'a', 2] print(('a' in arr) in arr) # -> True print('a' in arr in arr) # -> False 回答1: Section 6.10 of the Python language reference discusses comparison operators and comparison chaining. in is considered a comparison operator, and so behaves the same as < , etc. Without