Tutorial by Examples: re

break statement When a break statement executes inside a loop, control flow "breaks" out of the loop immediately: i = 0 while i < 7: print(i) if i == 4: print("Breaking from loop") break i += 1 The loop conditional will not be evaluated a...

Standard Creation It is recommended to use this form only when creating regex from dynamic variables. Use when the expression may change or the expression is user generated. var re = new RegExp(".*"); With flags: var re = new RegExp(".*", "gmi"); With a backsl...

There are several flags you can specify to alter the RegEx behaviour. Flags may be appended to the end of a regex literal, such as specifying gi in /test/gi, or they may be specified as the second argument to the RegExp constructor, as in new RegExp('test', 'gi'). g - Global. Finds all matches inst...

The String object has the following methods that accept regular expressions as arguments. "string".match(... "string".replace(... "string".split(... "string".search(... Match with RegExp console.log("string".match(/[i-n]+/)); console.log(&...

git remote add upstream git-repository-url Adds remote git repository represented by git-repository-url as new remote named upstream to the git repository

Assuming you set the upstream (as in the "setting an upstream repository") git fetch remote-name git merge remote-name/branch-name The pull command combines a fetch and a merge. git pull The pull with --rebase flag command combines a fetch and a rebase instead of merge. git pull ...

You can make Git ignore certain files and directories — that is, exclude them from being tracked by Git — by creating one or more .gitignore files in your repository. In software projects, .gitignore typically contains a listing of files and/or directories that are generated during the build proces...

Setting a specific Seed will create a fixed random-number series: random.seed(5) # Create a fixed state print(random.randrange(0, 10)) # Get a random integer between 0 and 9 # Out: 9 print(random.randrange(0, 10)) # Out: 4 Resetting the seed will create the same &qu...

import java.awt.Image; import javax.imageio.ImageIO; ... try { Image img = ImageIO.read(new File("~/Desktop/cat.png")); } catch (IOException e) { e.printStackTrace(); }

x > y x < y These operators compare two types of values, they're the less than and greater than operators. For numbers this simply compares the numerical values to see which is larger: 12 > 4 # True 12 < 4 # False 1 < 4 # True For strings they will compare lexicographical...

#include <stdio.h> enum Op { ADD = '+', SUB = '-', }; /* add: add a and b, return result */ int add(int a, int b) { return a + b; } /* sub: subtract b from a, return result */ int sub(int a, int b) { return a - b; } /* getmath: return the appropriate m...

Arrays can be created by enclosing a list of elements in square brackets ([ and ]). Array elements in this notation are separated with commas: array = [1, 2, 3, 4] Arrays can contain any kind of objects in any combination with no restrictions on type: array = [1, 'b', nil, [3, 4]]

Arrays of strings can be created using ruby's percent string syntax: array = %w(one two three four) This is functionally equivalent to defining the array as: array = ['one', 'two', 'three', 'four'] Instead of %w() you may use other matching pairs of delimiters: %w{...}, %w[...] or %w<...&...

2.0 array = %i(one two three four) Creates the array [:one, :two, :three, :four]. Instead of %i(...), you may use %i{...} or %i[...] or %i!...! Additionally, if you want to use interpolation, you can do this with %I. 2.0 a = 'hello' b = 'goodbye' array_one = %I(#{a} #{b} world) array_tw...

An empty Array ([]) can be created with Array's class method, Array::new: Array.new To set the length of the array, pass a numerical argument: Array.new 3 #=> [nil, nil, nil] There are two ways to populate an array with default values: Pass an immutable value as second argument. P...

The groupingBy(classifier, downstream) collector allows the collection of Stream elements into a Map by classifying each element in a group and performing a downstream operation on the elements classified in the same group. A classic example of this principle is to use a Map to count the occurrence...

If you ignore files by using a pattern but have exceptions, prefix an exclamation mark(!) to the exception. For example: *.txt !important.txt The above example instructs Git to ignore all files with the .txt extension except for files named important.txt. If the file is in an ignored folder, y...

Relational operators check if a specific relation between two operands is true. The result is evaluated to 1 (which means true) or 0 (which means false). This result is often used to affect control flow (via if, while, for), but can also be stored in variables. Equals "==" Checks whether...

The Promise.all() static method accepts an iterable (e.g. an Array) of promises and returns a new promise, which resolves when all promises in the iterable have resolved, or rejects if at least one of the promises in the iterable have rejected. // wait "millis" ms, then resolve with &quot...

The Promise.race() static method accepts an iterable of Promises and returns a new Promise which resolves or rejects as soon as the first of the promises in the iterable has resolved or rejected. // wait "milliseconds" milliseconds, then resolve with "value" function resolve(va...