operator-precedence

问题 This question already has answers here : What are the rules for evaluation order in Java? (5 answers) If parenthesis has a higher precedence then why is increment operator solved first? (5 answers) Closed 5 years ago . In this code: int y = 10; int z = (++y * (y++ + 5)); What I expected First y++ + 5 will be executed because of the precedence of the innermost parentheses. So value of y will be 11 and the value of this expression will be 15. Then ++y * () will be executed. So 12 * 15 = 180. So

问题 This question already has answers here : What are the rules for evaluation order in Java? (5 answers) If parenthesis has a higher precedence then why is increment operator solved first? (5 answers) Closed 5 years ago . In this code: int y = 10; int z = (++y * (y++ + 5)); What I expected First y++ + 5 will be executed because of the precedence of the innermost parentheses. So value of y will be 11 and the value of this expression will be 15. Then ++y * () will be executed. So 12 * 15 = 180. So

问题 This question already has answers here : What are the rules for evaluation order in Java? (5 answers) If parenthesis has a higher precedence then why is increment operator solved first? (5 answers) Closed 5 years ago . In this code: int y = 10; int z = (++y * (y++ + 5)); What I expected First y++ + 5 will be executed because of the precedence of the innermost parentheses. So value of y will be 11 and the value of this expression will be 15. Then ++y * () will be executed. So 12 * 15 = 180. So

问题 If I have the following code var num = 15 % 2 + 6 * 4; for example... I'd like to know what the output will be, specifically I would like to know the order of precedence for modulus (the operation executed by the % symbol). Will the modulus be performed before or after the addition and multiplication operations? Edit : I have already looked at the article people are linking me to MDN Operator Precedence And had done so before asking the question, but unfortunately it didn't contain enough

问题 Tuple elements may have side-effects, and some of them may depend on others. Consider this program: fn main() { let mut v = vec![1, 2]; match (v.pop(), v.pop()) { (Some(z), Some(y)) => println!("y = {}, z = {}", y, z), _ => unreachable!(), } } Does it output y = 1, z = 2 or y = 2, z = 1 ? A few rounds on the Rust Playground suggests the former on stable 1.32.0, but maybe it would change if I ran it more times, recompiled the compiler, changed compiler versions, etc. Is there a documented

问题 Tuple elements may have side-effects, and some of them may depend on others. Consider this program: fn main() { let mut v = vec![1, 2]; match (v.pop(), v.pop()) { (Some(z), Some(y)) => println!("y = {}, z = {}", y, z), _ => unreachable!(), } } Does it output y = 1, z = 2 or y = 2, z = 1 ? A few rounds on the Rust Playground suggests the former on stable 1.32.0, but maybe it would change if I ran it more times, recompiled the compiler, changed compiler versions, etc. Is there a documented

问题 One of the things I like the most of JavaScript is that the logical operators are very powerful: && can be used to safely extract the value of an object's field, and will return null if either the object or the field has not been initialized // returns null if param, param.object or param.object.field // have not been set field = param && param.object && param.object.field; || can be used to set default values: // set param to its default value param = param || defaultValue; Does PHP allow

问题 One of the things I like the most of JavaScript is that the logical operators are very powerful: && can be used to safely extract the value of an object's field, and will return null if either the object or the field has not been initialized // returns null if param, param.object or param.object.field // have not been set field = param && param.object && param.object.field; || can be used to set default values: // set param to its default value param = param || defaultValue; Does PHP allow

问题 I can't understand output of this program: #include<iostream> using namespace std; int main() { int x = 1 , y = 1, z = 1; cout << ( ++x || ++y && ++z ) << endl; //outputs 1; cout << x << " " << y << " " << z ; //x = 2 , y = 1 , z = 1; return 0; } Output: 1 2 1 1 If || is evaluated first then this output is fine, however this article says that && has a higher precedence than || , and thus it must be evaluated first. If this is the case then according to me output should be: 1 1 2 2 as ++y && +

问题 I can't understand output of this program: #include<iostream> using namespace std; int main() { int x = 1 , y = 1, z = 1; cout << ( ++x || ++y && ++z ) << endl; //outputs 1; cout << x << " " << y << " " << z ; //x = 2 , y = 1 , z = 1; return 0; } Output: 1 2 1 1 If || is evaluated first then this output is fine, however this article says that && has a higher precedence than || , and thus it must be evaluated first. If this is the case then according to me output should be: 1 1 2 2 as ++y && +