variables

问题 Here is the situation: I have one function which has local variable. I would like to assign that value to global variable and us it's value in another function. Here is the code: global_var = "abc"; function loadpages() { local_var = "xyz"; global_var= local_var; } function show_global_var_value() { alert(global_var); } I'm calling show_global_var_value() function in the HTML page but it shows the value = "xyz" not "abc" What am I doing wrong? 回答1: What you need to do apart from declaring

问题 Given n and k , I need to create all tuples of length k whose entries are from range(n) (0 to n-1) such that the tuple's entries are in dictionary order and there are parentheses in a particular format. Specifically, the tuple has parentheses around each pair, from inside out. For example, if n=3 and k=4 , then I would like the output to include something like (((0,0),1),2) , but not something like (((0,0),2),1) . The code below works for this specific instance. The issue is that I don't know

问题 The question that was put forth to me was: What will the value of uninitialized variables be in C++? Do we have to initialize all variables? What would be the rule for initializing variables? I've looked in my text as well as another text that I have on hand and can't seem to find the answer. Here's what I've attempted: The value of uninitialized variables in C++ depends on the previous value stored in the memory that the uninitialized variable is assigned to. Initializing all variables is

问题 The question that was put forth to me was: What will the value of uninitialized variables be in C++? Do we have to initialize all variables? What would be the rule for initializing variables? I've looked in my text as well as another text that I have on hand and can't seem to find the answer. Here's what I've attempted: The value of uninitialized variables in C++ depends on the previous value stored in the memory that the uninitialized variable is assigned to. Initializing all variables is

问题 I am working with a script that has a variable called PRODUCT_VERSION . The version comes with a dot (for example 6.0 ). I need to remove the dot and save the result in another variable. So far I come with this, but it does not work correctly PRD_VER=$(sed "s/$PRODUCT_VERSION/\.//g") 回答1: $ PRODUCT_VERSION=6.0 $ PRD_VER=${PRODUCT_VERSION/.} $ echo $PRD_VER 60 Bash String Manipulation Examples 回答2: This might work for you (GNU sed & bash): NEW=$(sed 's/\.//g' <<<"$OLD") or NEW=$(echo "$OLD" |

问题 I am working with a script that has a variable called PRODUCT_VERSION . The version comes with a dot (for example 6.0 ). I need to remove the dot and save the result in another variable. So far I come with this, but it does not work correctly PRD_VER=$(sed "s/$PRODUCT_VERSION/\.//g") 回答1: $ PRODUCT_VERSION=6.0 $ PRD_VER=${PRODUCT_VERSION/.} $ echo $PRD_VER 60 Bash String Manipulation Examples 回答2: This might work for you (GNU sed & bash): NEW=$(sed 's/\.//g' <<<"$OLD") or NEW=$(echo "$OLD" |

问题 I am working with a script that has a variable called PRODUCT_VERSION . The version comes with a dot (for example 6.0 ). I need to remove the dot and save the result in another variable. So far I come with this, but it does not work correctly PRD_VER=$(sed "s/$PRODUCT_VERSION/\.//g") 回答1: $ PRODUCT_VERSION=6.0 $ PRD_VER=${PRODUCT_VERSION/.} $ echo $PRD_VER 60 Bash String Manipulation Examples 回答2: This might work for you (GNU sed & bash): NEW=$(sed 's/\.//g' <<<"$OLD") or NEW=$(echo "$OLD" |

问题 This function is written in JavaScript but I think that the concept can be implemented with some other programming languages. function uniteUnique(arr) { let seenBefore = []; //the accumulating array for (let item of arguments) { if (typeof (item) == "object") { uniteUnique(...item); } else if (!seenBefore.includes(item)) { seenBefore.push(item); } } return seenBefore; } In short, the function iterates over arrays it receives as arguments, which may or may not contain other arrays themselves.

问题 This function is written in JavaScript but I think that the concept can be implemented with some other programming languages. function uniteUnique(arr) { let seenBefore = []; //the accumulating array for (let item of arguments) { if (typeof (item) == "object") { uniteUnique(...item); } else if (!seenBefore.includes(item)) { seenBefore.push(item); } } return seenBefore; } In short, the function iterates over arrays it receives as arguments, which may or may not contain other arrays themselves.

问题 As far as I know, interfaces cannot be instantiated. If this is true, why does the below code compile and execute? It allows you to create a variable interface. Why is this possible? Interface: public interface IDynamicCode<out TCodeOut> { object DynamicClassInstance { get; set; } TCodeOut Execute(string value = ""); } InCode: var x = new IDynamicCode<string>[10]; Result: UPDATE: It only happens when array declared. Not a single instance. 回答1: You're not instantiating an interface, but an