Conditions and Loops

you can watch parallel the video for C/C++ (german): https://www.youtube.com/watch?v=aob0SwTaF2Q&list=PLEWVM-KBUSpmWSfyoFdD_hLWAY_9tTgi5&index=17 https://www.youtube.com/watch?v=gjRcvn9TM-o&list=PLEWVM-KBUSpmWSfyoFdD_hLWAY_9tTgi5&index=18 https://www.youtube.com/watch?v=lxNX3jXdo6M&list=PLEWVM-KBUSpmWSfyoFdD_hLWAY_9tTgi5&index=19 https://www.youtube.com/watch?v=lCQii8m_5Fw&list=PLEWVM-KBUSpmWSfyoFdD_hLWAY_9tTgi5&index=20 https://www.youtube.com/watch?v=5bm9GxAr_4E&list=PLEWVM-KBUSpmWSfyoFdD_hLWAY_9tTgi5&index=21 https://www.youtube.com/watch?v=5cE_HfsLpP0&list=PLEWVM-KBUSpmWSfyoFdD_hLWAY_9tTgi5&index=22

import ROOT

import fortranmagic
%load_ext fortranmagic
import os
import sys

import numpy as np

if sys.platform.startswith("win"):
        # Depends of system, python builds, and compilers compatibility.
        # See below.
    f_config = "--fcompiler=gnu95 --compiler=mingw32"
else:
        # For Unix, compilers are usually more compatible.
    f_config = ""

    # Disable only deprecated NumPy API warning without disable any APIs.
f_config += " --extra '-DNPY_NO_DEPRECATED_API=0'"

%fortran_config {f_config}

New default arguments for %fortran:
	 --extra '-DNPY_NO_DEPRECATED_API=0'

Conditions

c++

%%cpp
int i=7;
if(i==5){
    cout<<"equals five!"<<endl;
} else if(i==6){                                   //this part can also be left out
    cout<<"equals six!"<<endl;
} else {                                             //this part can also be left out
    cout<<"neither five nor six!"<<endl;
}

neither five nor six!

%%cpp
int i=5;
if(i==5) cout<<"equals five!"<<endl;
else if(i==6) cout<<"equals six!"<<endl;
else cout<<"neither five nor six!"<<endl;

equals five!

c

%%cpp
int i=5;
if(i==5){
    printf("equals five!");
} else if(i==6){                                   //this part can also be left out
    printf("equals six!");
} else {                                             //this part can also be left out
    printf("neither five nor six!");
}

equals five!

javascript

%%js //the next line is only necessary in jupyter notebooks
element.setAttribute('style', 'white-space: pre;');console.log=function(text){element.textContent+=text+"\n"}

let i=5
if(i==5){
    console.log("equals five!");
} else if(i==6){                                   //this part can also be left out
    console.log("equals six!");
} else {                                             //this part can also be left out
    console.log("neither five nor six!");
}

Python

i=5

if i==5:
    print("equals five!")
elif i==6:
    print("equals six!")
else:
    print("neither five nor six")

equals five!

Fortran

%%fortran 

! program and subroutine exchanged due to jupyternotebook

! program main
subroutine main()
    implicit none

    integer :: i = 5

    if (i .eq. 5) then
        print *,"equals five!"
    else if (i .eq. 6) then
        print *,"equals six!"
    else
        print *,"neither five nor six"
    endif !"end if" is also possible
! end program
end subroutine main

main()

 equals five!

Loops

c++

%%cpp
string s{"Hallo"};
cout<<"***** While Loop *****"<<endl;
int i=0;
while(i<10){//the same in c
    cout <<i<<endl;
    ++i;
}

cout<<"***** Do-While Loop *****"<<endl;
do{//the same in c
    cout <<i<<endl;
    --i;
}while(i>0);

cout<<"***** For Loop *****"<<endl;
for(int i=0;i<10;++i){//the same in c
    if(i==5) continue;
    cout <<i<<endl;
    if(i==8) break;
}

cout<<"This only works in c++"<<endl;
for(auto &c:s){
    cout <<c<<endl;
}

***** While Loop *****
0
1
2
3
4
5
6
7
8
9
***** Do-While Loop *****
10
9
8
7
6
5
4
3
2
1
***** For Loop *****
0
1
2
3
4
6
7
8
This only works in c++
H
a
l
l
o

C

%%cpp
char s[]="Hallo";
printf("***** While Loop *****\n");
int i=0;
while(i<10){
    printf("%d\n",i);
    ++i;
}

printf("***** Do-While Loop *****\n");
do{
    printf("%d\n",i);
    --i;
}while(i>0);
cout<<"***** For Loop *****"<<endl;

for(int i=0;i<10;++i){
    if(i==5) continue;
    printf("%d\n",i);
    if(i==8) break;
}

printf("***** Looping over a string in c *****\n");
//a c string is actually an array
for(int i=0;i<sizeof(s)/sizeof(char);++i){
    printf("%c\n",s[i]);
}

***** While Loop *****
0
1
2
3
4
5
6
7
8
9
***** Do-While Loop *****
10
9
8
7
6
5
4
3
2
1
***** For Loop *****
0
1
2
3
4
6
7
8
***** Looping over a string in c *****
H
a
l
l
o

Javascript

%%js //the next line is only necessary in jupyter notebooks
element.setAttribute('style', 'white-space: pre;');console.log=function(text){element.textContent+=text+"\n"}

let s="Hallo"
console.log("***** While Loop *****");
let i=0;
while(i<10){//the same in c
    console.log(i);
    ++i;
}

console.log("***** Do-While Loop *****");
do{
    console.log(i);
    --i;
}while(i>0);

console.log("***** For Loop *****");
for(let i=0;i<10;++i){
    if(i==5) continue;
    console.log(i);
    if(i==8) break;
}

console.log("***** iterate over string c-style *****")
for (let i = 0; i < s.length; i++) {
    console.log(s[i]);
}

console.log("***** iterate over string c++-style *****")
for (const c of s) {
    console.log(c);
};

console.log("***** functional way but slower *****")
s.split('').forEach(function(c) {
    console.log(c);
});

Python

s = "Hallo"
a=[1,2,3,4,5];
i=0;
print("***** while loop *****")
while i<10:
    print(i);
    i+=1

print("***** do while loop does not exist *****")

print("***** For loop *****");
for i in range(0,10):
    if i==5: continue
    print(i)
    if i==8: break
    
print("***** iterate over string *****")
for c in s:
    print(c)

print("***** iterate over array *****")
for i in a:
    print(i)

print("***** iterate over array with index *****")
for i in range(len(a)):
    print(a[i])

***** while loop *****
0
1
2
3
4
5
6
7
8
9
***** do while loop does not exist *****
***** For loop *****
0
1
2
3
4
6
7
8
***** iterate over string *****
H
a
l
l
o
***** iterate over array *****
1
2
3
4
5
***** iterate over array with index *****
1
2
3
4
5

for i in range(0,10):
    print(i)
else:
    print ("fertig")

0
1
2
3
4
5
6
7
8
9
fertig

Fortan

%%fortran 

! program and subroutine exchanged due to jupyternotebook

! program main
subroutine main()
    implicit none

    character (len=5) :: s="Hallo"
    integer :: i;
    print *,"***** While Loop *****"

    i=0;
    do while(i .lt. 10)
        print *,i
        i=i+1
    enddo ! "end do" also possible

    do while(.true.)
        print *,i
        i=i-1;
        if (i.le.0) exit
    enddo

    do i=0,10,1
        if (i.eq.5) then
            cycle
        endif
        print *,i
        if (i.eq.8) then
            exit
        endif
    enddo

    do i=1,len_trim(s),1
        print *,s(i:i)
    enddo

! end program
end subroutine main

main()

 ***** While Loop *****
           0
           1
           2
           3
           4
           5
           6
           7
           8
           9
          10
           9
           8
           7
           6
           5
           4
           3
           2
           1
           0
           1
           2
           3
           4
           6
           7
           8
 H
 a
 l
 l
 o

Switch Case

c++

%%cpp

for(int i=0;i<10;++i){
    switch(i){
    case 1:
        cout<<"one"<<endl;
        break;
    case 5:
        cout<<"five"<<endl;
        break;
    default:
        cout<<"..."<<endl;
    }
        
}

...
one
...
...
...
five
...
...
...
...

c

%%cpp

for(int i=0;i<10;++i){
    switch(i){
    case 1:
        printf("one\n");
        break;
    case 5:
        printf("five\n");
        break;
    default:
        printf("...\n");
    }
        
}

...
one
...
...
...
five
...
...
...
...

javascript

%%js //the next line is only necessary in jupyter notebooks
element.setAttribute('style', 'white-space: pre;');console.log=function(text){element.textContent+=text+"\n"}

for(let i=0;i<10;++i){
    switch(i){
    case 1:
        console.log("one\n");
        break;
    case 5:
        console.log("five\n");
        break;
    default:
        console.log("...\n");
    }
        
}

Python

supports match case since python Version 3.10

for i in range(0,10):
    match i:
        case 1:
            print("one");
        case 5:
            print("five");
        case _:
            print("...");
            

...
one
...
...
...
five
...
...
...
...

Fortran

%%fortran 

! program and subroutine exchanged due to jupyternotebook

! program main
subroutine main()
    implicit none

    integer :: i

    do i=0,9,1
        select case (i)
            case(1)
                print *,"one"
            case(5)
                print *,"five"
            case default
                print *,"..."
        end select
    enddo

! end program
end subroutine main

main()

 ...
 one
 ...
 ...
 ...
 five
 ...
 ...
 ...
 ...