For most purposes, you probably won’t notice a difference. However, foreach reads each line into a list (not an array) before going through it line by line, whereas while reads one line at a time. As foreach will use more memory and require processing time upfront, it is generally recommended to use while to iterate … Read more
Yes* Yes, usually (and in your case) it does break out of the loop and returns from the method. An Exception One exception is that if there is a finally block inside the loop and surrounding the return statement then the code in the finally block will be executed before the method returns. The finally … Read more
but on the other hand it creates a completely useless list of integers just to loop over them. Isn’t it a waste of memory, especially as far as big numbers of iterations are concerned? That is what xrange(n) is for. It avoids creating a list of numbers, and instead just provides an iterator object. In … Read more
The problem in this particular case is that you return from within the for-expression. That in turn gets translated into a throw of a NonLocalReturnException, which is caught at the enclosing method. The optimizer can eliminate the foreach but cannot yet eliminate the throw/catch. And throw/catch is expensive. But since such nested returns are rare … Read more
An if statement runs its else clause if its condition evaluates to false. Identically, a while loop runs the else clause if its condition evaluates to false. This rule matches the behavior you described: In normal execution, the while loop repeatedly runs until the condition evaluates to false, and therefore naturally exiting the loop runs … Read more
As tadman stated in the comment under your question. The best approach should use a modulus operator (%) with 3. Place your separating condition at the start of each iteration. (Demo) Like this: $x=0; // I prefer to increment starting from zero. // This way I can use the same method inside a foreach loop … Read more
Because you typed ‘a‘ and ‘\n‘… The ‘\n‘ is a result of pressing the [ENTER] key after typing into your terminal/console’s input line. The getchar() function will return each character, one at a time, until the input buffer is clear. So your loop will continue to cycle until getchar() has eaten any remaining characters from … Read more
Though Dennis Williamson’s answer is absolutely correct, it creates a subshell, which will prevent you from setting any variables inside the loop. You may consider using process substitution, as so: while IFS= read -d ” -r file; do grep ‘<image’ “$file” > /dev/null && echo “$file” | tee -a embeded_images.txt done < <(find people -name … Read more
I’ll just quote the Java Language Specification, as it’s rather clear on this: This section is devoted to a precise explanation of the word “reachable.” The idea is that there must be some possible execution path from the beginning of the constructor, method, instance initializer or static initializer that contains the statement to the statement … Read more
They are equivalent, even if you turn the optimizer off. Example: #include <stdio.h> extern void f(void) { while(1) { putchar(‘ ‘); } } extern void g(void) { for(;;){ putchar(‘ ‘); } } extern void h(void) { z: putchar(‘ ‘); goto z; } Compile with gcc -O0 gives equivalent assembly for all 3 functions: f: ; … Read more