Programming languages

Basics

Programming language

An artificial language used to write instructions that can be translated into machine language (or subroutines) and then executed by a computer.

Syntax

Syntax is the set of rules that defines the combinations of symbols that are considered to be a correctly structured document or fragment in that language.

Syntax is generally distinguished into three levels: words, phrases and context.

Semantics

Semantics is the field concerned with the rigorous mathematical study of the meaning of programming languages. It does so by evaluating the meaning of syntactically legal strings defined by a specific programming language, showing the computation involved.

Programming languages

Assembly

Fortran

program ProjectEuler
  implicit none
  integer :: i, s = 0

  do i=1,1000
    if (modulo(i, 3) == 0 .OR. modulo(i, 5) == 0) then
      s = s + i
    endif
  enddo

  write (*,'(A, I6)') "Solution: ", s
end program

C

#include<stdio.h>

int solution(int n);

int main(void) {

  printf("Solution: %d\n", solution(1000));

  return 0;
}

int solution(int n) {
  int sum = 0;

  for (int i = 1; i <= n; i++) {
    if (i % 3 == 0 || i % 5 == 0) {
      sum += i;
    }
  }

  return sum;
}

Haskell

multiples = filter (\x -> mod x 3 == 0 || mod x 5 == 0)

solution = sum . multiples

result arr = "Solution: " ++ show arr

main = putStrLn $ result $ solution [0..1000]

Java

import java.util.stream.IntStream;

public class ProjectEuler {
  public static void main (String[] args) {
    System.out.println("Solution: " + new Solution(1000).run());
  }
}

class Solution {
  int n;

  public Solution(int n) {
    this.n = n;
  }

  int run() {
    return IntStream.rangeClosed(0, n)
      .filter(x -> x % 3 == 0 || x % 5 == 0)
      .sum();
  }
}

Ruby

def solution(n)
  (1..n)
    .to_a
    .select{ |x| x % 3 == 0 || x % 5 == 0 }
    .reduce(:+)
end

puts "Solution: #{solution 1000}"

Clojure

(ns project_euler)

(defn result [n]
  (->>
    (str "Solution: " n)
    println))

(defn solution [n]
  (->>
    (range n)
    (filter (fn [x] (or (= (mod x 3) 0) (= (mod x 5) 0))))
    (reduce +)))

(result (solution 1000))

JavaScript

function solution(n) {
  return Array.from(Array(n))
    .map((x, i) => i + 1)
    .filter(x => x % 3 == 0 | x % 5 == 0)
    .reduce((x, akk) => x + akk,0);
}

console.log(`Solution: ${solution(1000)}`);

Programming and Business

Demand

In fact the US Department of Labor estimates that there will be 1.4 million computer specialist job openings by 2020, and enough qualified graduates to fill…

30%

Salary

Java

$115,000

Python

$100,000

R

$100,000

Objective-C/Swift

$100,000 up to 6 figures

C#

$90,000

JavaScript

$90,000

Perl

$80,000

SQL

$80,000

Ruby

$75,000

C

$60,000 - $80,000

PHP

$75,000

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