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Flowcharts: Mermaid og Graphviz

Omsætter den samme pseudokode til et Mermaid- eller Graphviz-flowchart. Begge motorer deler samme semantik; Graphviz prioriterer deterministisk geometri.

Diagrammerne nedenfor gengives direkte af MkDocs fra Mermaid- og Graphviz-kilderne; der bruges ingen omtrentlige statiske billeder.

Komplet eksempel: gæt et tal

Først læses n som øvre grænse. Programmet vælger tilfældigt et mål mellem 1 og n og beder derefter om gæt m. Når tallet findes, afslutter Afbryde løkken.

Læse n
mål = tilfældigMellem(1, n)
m = mål + 1
Mens m er ikke lig med mål:
    Læse m
    Hvis m > mål Så:
        Vise "For stort!"
    Ellers Hvis m < mål Så:
        Vise "For lille!"
    Ellers:
        Vise "Vundet!"
        Afbryde
    Slut
Slut

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3[/"Læse n"/]
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    n4["mål = tilfældigMellem(1, n)"]
    %% pseudocode-edge e1 n3 n4 normal
    n3 e1@--> n4
    %% pseudocode-sequence e1 n3 n4
    n5["m = mål + 1"]
    %% pseudocode-edge e2 n4 n5 normal
    n4 e2@--> n5
    %% pseudocode-sequence e2 n4 n5
    n6{"Mens m er ikke lig med mål ?"}
    %% pseudocode-edge e3 n5 n6 normal
    n5 e3@--> n6
    %% pseudocode-sequence e3 n5 n6
    subgraph loop1_body[" "]
        direction TB
    n7[/"Læse m"/]
    n8{"m #62; mål ?"}
    %% pseudocode-edge e4 n7 n8 normal
    n7 e4@--> n8
    %% pseudocode-sequence e4 n7 n8
    n9[/"Vise 'For stort!'"/]
    %% pseudocode-edge e5 n8 n9 branch
    n8 e5@-->|"Ja"| n9
    n10{"m #60; mål ?"}
    %% pseudocode-edge e6 n8 n10 branch
    n8 e6@-->|"Nej"| n10
    n11[/"Vise 'For lille!'"/]
    %% pseudocode-edge e7 n10 n11 branch
    n10 e7@-->|"Ja"| n11
    n12[/"Vise 'Vundet!'"/]
    %% pseudocode-edge e8 n10 n12 branch
    n10 e8@-->|"Nej"| n12
    n13["Afbryde"]
    %% pseudocode-edge e9 n12 n13 normal
    n12 e9@--> n13
    %% pseudocode-sequence e9 n12 n13
    n14((" ")):::pseudocodeGhost
    %% pseudocode-edge e10 n9 n14 normal
    n9 e10@--- n14
    %% pseudocode-sequence e10 n9 n14
    %% pseudocode-edge e11 n11 n14 normal
    n11 e11@--- n14
    %% pseudocode-sequence e11 n11 n14
    end
    style loop1_body fill:none,stroke:none
    %% pseudocode-edge e12 n6 n7 branch
    n6 e12@-->|"Ja"| n7
    %% pseudocode-loop-continue e12 n6 n7
    %% pseudocode-edge e13 n14 n6 loop_back
    n14 e13@--> n6
    %% pseudocode-loop-back e13 n14 n6
    %% pseudocode-edge e14 n6 n2 branch
    n6 e14@-->|"Nej"| n2
    %% pseudocode-loop-exit e14 n6 n2
    %% pseudocode-edge e15 n13 n2 normal
    n13 e15@--> n2
    %% pseudocode-sequence e15 n13 n2
    classDef pseudocodeGhost fill:transparent,stroke:transparent,color:transparent;

pseudocoden1:s->n3:nn3:s->n4:nn4:s->n5:nn5:s->n6:nn6:s->n7:nJan6:e->__exit_top_3:wNejn7:s->n8:nn8:s->n9:nJan8:e->n10:nNejn9:s->n14:nn10:s->n11:nJan10:e->n12:nNejn11:s->n14:nn12:s->n13:nn13:s->n2:nn14:w->__return_bottom_1:e__return_bottom_1:n->__return_top_2:s__return_top_2:e->n6:w__exit_top_3:s->__exit_bottom_4:n__exit_bottom_4:w->n2:en1Startn2Slutn3Læse nn4mål = tilfældigMellem(1, n)n5m = mål + 1n6Mens m er ikke lig med mål ?n7Læse mn8m > mål ?n9Vise "For stort!"n10m < mål ?n11Vise "For lille!"n12Vise "Vundet!"n13Afbryde

Vigtigste programmeringsstrukturer

De følgende eksempler viser de mest almindelige kontrolstrukturer hver for sig, så deres Mermaid- og Graphviz-visning hurtigt kan sammenlignes.

Betingelse: Hvis … Så … Ellers …

x = 5
Hvis x > 0 Så:
    Vise "positiv"
Ellers:
    Vise "nul eller negativ"
Slut

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3["x = 5"]
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    n4{"x #62; 0 ?"}
    %% pseudocode-edge e1 n3 n4 normal
    n3 e1@--> n4
    %% pseudocode-sequence e1 n3 n4
    n5[/"Vise 'positiv'"/]
    %% pseudocode-edge e2 n4 n5 branch
    n4 e2@-->|"Ja"| n5
    n6[/"Vise 'nul eller negativ'"/]
    %% pseudocode-edge e3 n4 n6 branch
    n4 e3@-->|"Nej"| n6
    %% pseudocode-edge e4 n5 n2 normal
    n5 e4@--> n2
    %% pseudocode-sequence e4 n5 n2
    %% pseudocode-edge e5 n6 n2 normal
    n6 e5@--> n2
    %% pseudocode-sequence e5 n6 n2

pseudocoden1:s->n3:nn3:s->n4:nn4:s->n5:nJan4:e->n6:nNejn5:s->n2:nn6:s->n2:nn1Startn2Slutn3x = 5n4x > 0 ?n5Vise "positiv"n6Vise "nul eller negativ"

Løkke: For … fra … til …

total = 0
For i fra 1 til 5:
    total = total + i
Slut
Vise total

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3["total = 0"]
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    n4{"For i fra 1 til 5"}
    %% pseudocode-edge e1 n3 n4 normal
    n3 e1@--> n4
    %% pseudocode-sequence e1 n3 n4
    subgraph loop1_body[" "]
        direction TB
    n5["total = total + i"]
    end
    style loop1_body fill:none,stroke:none
    %% pseudocode-edge e2 n4 n5 branch
    n4 e2@-->|"Ja"| n5
    %% pseudocode-loop-continue e2 n4 n5
    %% pseudocode-edge e3 n5 n4 loop_back
    n5 e3@-->|"(i = i + 1)"| n4
    %% pseudocode-loop-back e3 n5 n4
    n6[/"Vise total"/]
    %% pseudocode-edge e4 n4 n6 branch
    n4 e4@-->|"Nej"| n6
    %% pseudocode-loop-exit e4 n4 n6
    %% pseudocode-edge e5 n6 n2 normal
    n6 e5@--> n2
    %% pseudocode-sequence e5 n6 n2

pseudocoden1:s->n3:nn3:s->n4:nn4:s->n5:nJan4:e->__exit_top_3:wNejn5:w->__return_bottom_1:e(i = i + 1)n6:s->n2:n__return_bottom_1:n->__return_top_2:s__return_top_2:e->n4:w__exit_top_3:s->__exit_bottom_4:n__exit_bottom_4:w->n6:en1Startn2Slutn3total = 0n4For i fra 1 til 5n5total = total + in6Vise total

Løkke: For … fra … til … med trin …

For i fra 0 til 10 med trin 2:
    Vise i
Slut

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3{"For i fra 0 til 10 med trin 2"}
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    subgraph loop1_body[" "]
        direction TB
    n4[/"Vise i"/]
    end
    style loop1_body fill:none,stroke:none
    %% pseudocode-edge e1 n3 n4 branch
    n3 e1@-->|"Ja"| n4
    %% pseudocode-loop-continue e1 n3 n4
    %% pseudocode-edge e2 n4 n3 loop_back
    n4 e2@-->|"(i = i + 2)"| n3
    %% pseudocode-loop-back e2 n4 n3
    %% pseudocode-edge e3 n3 n2 branch
    n3 e3@-->|"Nej"| n2
    %% pseudocode-loop-exit e3 n3 n2

pseudocoden1:s->n3:nn3:s->n4:nJan3:e->__exit_top_3:wNejn4:w->__return_bottom_1:e(i = i + 2)__return_bottom_1:n->__return_top_2:s__return_top_2:e->n3:w__exit_top_3:s->__exit_bottom_4:n__exit_bottom_4:w->n2:en1Startn2Slutn3For i fra 0 til 10 med trin 2n4Vise i

Løkke: For … I …

For c I "Hej":
    Vise c
Slut

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3{"For c I 'Hej'"}
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    subgraph loop1_body[" "]
        direction TB
    n4[/"Vise c"/]
    end
    style loop1_body fill:none,stroke:none
    %% pseudocode-edge e1 n3 n4 branch
    n3 e1@-->|"Ja"| n4
    %% pseudocode-loop-continue e1 n3 n4
    %% pseudocode-edge e2 n4 n3 loop_back
    n4 e2@--> n3
    %% pseudocode-loop-back e2 n4 n3
    %% pseudocode-edge e3 n3 n2 branch
    n3 e3@-->|"Nej"| n2
    %% pseudocode-loop-exit e3 n3 n2

pseudocoden1:s->n3:nn3:s->n4:nJan3:e->__exit_top_3:wNejn4:w->__return_bottom_1:e__return_bottom_1:n->__return_top_2:s__return_top_2:e->n3:w__exit_top_3:s->__exit_bottom_4:n__exit_bottom_4:w->n2:en1Startn2Slutn3For c I "Hej"n4Vise c

Løkke: Mens …

i = 0
Mens i < 3:
    Vise i
    i = i + 1
Slut

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3["i = 0"]
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    n4{"Mens i #60; 3 ?"}
    %% pseudocode-edge e1 n3 n4 normal
    n3 e1@--> n4
    %% pseudocode-sequence e1 n3 n4
    subgraph loop1_body[" "]
        direction TB
    n5[/"Vise i"/]
    n6["i = i + 1"]
    %% pseudocode-edge e2 n5 n6 normal
    n5 e2@--> n6
    %% pseudocode-sequence e2 n5 n6
    end
    style loop1_body fill:none,stroke:none
    %% pseudocode-edge e3 n4 n5 branch
    n4 e3@-->|"Ja"| n5
    %% pseudocode-loop-continue e3 n4 n5
    %% pseudocode-edge e4 n6 n4 loop_back
    n6 e4@--> n4
    %% pseudocode-loop-back e4 n6 n4
    %% pseudocode-edge e5 n4 n2 branch
    n4 e5@-->|"Nej"| n2
    %% pseudocode-loop-exit e5 n4 n2

pseudocoden1:s->n3:nn3:s->n4:nn4:s->n5:nJan4:e->__exit_top_3:wNejn5:s->n6:nn6:w->__return_bottom_1:e__return_bottom_1:n->__return_top_2:s__return_top_2:e->n4:w__exit_top_3:s->__exit_bottom_4:n__exit_bottom_4:w->n2:en1Startn2Slutn3i = 0n4Mens i < 3 ?n5Vise in6i = i + 1

Løkke: Gentag … gange

Gentage 3 gange:
    Vise "Hej"
Slut

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3{"Gentage 3 gange"}
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    subgraph loop1_body[" "]
        direction TB
    n4[/"Vise 'Hej'"/]
    end
    style loop1_body fill:none,stroke:none
    %% pseudocode-edge e1 n3 n4 branch
    n3 e1@-->|"Ja"| n4
    %% pseudocode-loop-continue e1 n3 n4
    %% pseudocode-edge e2 n4 n3 loop_back
    n4 e2@--> n3
    %% pseudocode-loop-back e2 n4 n3
    %% pseudocode-edge e3 n3 n2 branch
    n3 e3@-->|"Nej"| n2
    %% pseudocode-loop-exit e3 n3 n2

pseudocoden1:s->n3:nn3:s->n4:nJan3:e->__exit_top_3:wNejn4:w->__return_bottom_1:e__return_bottom_1:n->__return_top_2:s__return_top_2:e->n3:w__exit_top_3:s->__exit_bottom_4:n__exit_bottom_4:w->n2:en1Startn2Slutn3Gentage 3 gangen4Vise "Hej"

Løkke: Gentag … Indtil …

i = 0
Gentage:
    Vise i
    i = i + 1
Indtil i >= 3

%%{init: {"flowchart":{"curve":"basis","nodeSpacing":55,"rankSpacing":72,"htmlLabels":false},"layout":"elk","look":"classic","elk":{"preset":"modelOrder","nodePlacementStrategy":"LINEAR_SEGMENTS","nodePlacementAlignment":"NONE","layeringStrategy":"NETWORK_SIMPLEX","cycleBreakingStrategy":"MODEL_ORDER","considerModelOrder":"NODES_AND_EDGES","forceNodeModelOrder":true,"keepEntryNodeOnTop":true,"straightenEdges":true,"lineHops":false,"mergeEdges":false},"htmlLabels":false}}%%
%% pseudocode-layout-profile: validated-loop-attached-edges-v22
flowchart TD
    n1(["Start"])
    n2(["Slut"])
    n3["i = 0"]
    %% pseudocode-edge e0 n1 n3 normal
    n1 e0@--> n3
    %% pseudocode-sequence e0 n1 n3
    subgraph loop1[" "]
        direction TB
        subgraph loop1_body[" "]
            direction TB
    n4[/"Vise i"/]
    n5["i = i + 1"]
    %% pseudocode-edge e1 n4 n5 normal
    n4 e1@--> n5
    %% pseudocode-sequence e1 n4 n5
        end
    style loop1_body fill:none,stroke:none
        subgraph loop1_condition[" "]
            direction TB
    n6{"i #62;= 3 ?"}
        end
    style loop1_condition fill:none,stroke:none
    %% pseudocode-edge e2 n5 n6 normal
    n5 e2@--> n6
    %% pseudocode-sequence e2 n5 n6
    end
    style loop1 fill:none,stroke:none
    %% pseudocode-edge e3 n3 n4 normal
    n3 e3@--> n4
    %% pseudocode-sequence e3 n3 n4
    %% pseudocode-edge e4 n6 n4 loop_back
    n6 e4@-->|"Nej"| n4
    %% pseudocode-loop-back e4 n6 n4
    %% pseudocode-edge e5 n6 n2 branch
    n6 e5@-->|"Ja"| n2
    %% pseudocode-loop-exit e5 n6 n2

pseudocoden1:s->n3:nn3:s->n4:nn4:s->n5:nn5:s->n6:nn6:w->__return_bottom_1:eNejn6:e->__exit_top_3:wJa__return_bottom_1:n->__return_top_2:s__return_top_2:e->n4:w__exit_top_3:s->__exit_bottom_4:n__exit_bottom_4:w->n2:en1Startn2Slutn3i = 0n4Vise in5i = i + 1n6i >= 3 ?