Question

我的程序遇到printRecipeOfTheDay函数问题。比方说，例如0由程序随机选择并分配给我创建的星期一变量，当我将“recipe1”传递给函数“printRecipeOfTheDay”时，我没有输出或空值。关于我可能搞砸了什么的任何想法？

        if monday == 0 {
            fmt.Println(0)
            printRecipeOfTheDay(recipe1)
        } else if monday == 1 {
            fmt.Println(1)

整个计划如下：

package main

import (
    "fmt"
    "math/rand"
    "time"
)

//Struct for Recipe below
type Recipe struct { //Struct for recipe information
    name        string
    prepTime    int
    cookTime    int
    Ingredients []string //this is now a slice that will accept multiple elements
    ID          int
    Yield       int
}

//function to print Recipe
func printRecipe(recipe Recipe) {
    fmt.Printf("Recipe Name : %s\n", recipe.name)
    fmt.Printf("Prep Time : %d\n", recipe.prepTime)
    fmt.Printf("Cook Time : %d\n", recipe.cookTime)
    fmt.Printf("Ingredients : %s\n", recipe.Ingredients)
    fmt.Printf("Recipe ID : %d\n", recipe.ID)
}

//Returns total time by addings cookTime and prepTime
func totalTime(recipe Recipe) {
    fmt.Printf("The total time for this recipe is %d\n", recipe.cookTime+recipe.prepTime)
}

func main() {
    var recipe1 Recipe //Declare recipe1 of Type Recipe
    var recipe2 Recipe
    var recipe3 Recipe

    //choose random number for recipe
    r := rand.New(rand.NewSource(time.Now().UnixNano()))
    i := r.Perm(5)
    fmt.Printf("%v\n", i)
    fmt.Printf("%d\n", i[0])

    //assign slices of int from Perm to variables assigned days of the week
    var monday = i[0]
    var tuesday = i[1]
    var wednesday = i[2]
    var thursday = i[3]
    var friday = i[4]

    //testing printing of variables assigned to days
    fmt.Printf("This is for the day Monday %d\n", monday)
    fmt.Printf("%d\n", tuesday)
    fmt.Printf("%d\n", wednesday)
    fmt.Printf("%d\n", thursday)
    fmt.Printf("%d\n", friday)

    //logic for Mondays Recipe
    if monday == 0 {
        fmt.Println(0)
        printRecipeOfTheDay(recipe1)
    } else if monday == 1 {
        fmt.Println(1)
        printRecipeOfTheDay(recipe2)
    } else if monday == 2 {
        fmt.Println(2)
        printRecipeOfTheDay(recipe3)
    } else if monday == 3 {
        fmt.Println(3)
    }
    /* recipe1 specifications */
    recipe1.name = "BBQ Pulled Chicken"
    recipe1.prepTime = 25
    recipe1.cookTime = 5
    recipe1.Ingredients = append(
        recipe1.Ingredients,
        "1 8-ounce can reduced-sodium tomato sauce",
    )
    recipe1.Ingredients = append(
        recipe1.Ingredients,
        "1/2 medium onion (grated),",
    )
    recipe1.ID = 1
    recipe1.Yield = 8

    /* Recipe 2 specifications */

    recipe2.name = "Steak Tacos with Pineapple"
    recipe2.prepTime = 45
    recipe2.cookTime = 45
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "3 tablespoons soy sauce,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 tablespoon finely grated garlic,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 tablespoon finely grated peeled fresh ginger,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 1/2 pounds skirt steak, cut into 5-inch lengths,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "Salt",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "Pepper",
    )
    recipe2.ID = 2
    recipe2.Yield = 4

    recipe3.name = "Simple Lemon Herb Chicken"
    recipe3.prepTime = 10
    recipe3.cookTime = 15
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "2 skinless boneless chicken breast halves,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 Lemon,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "Salt and Pepper to taste,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 tablespoon olive oil,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "2 sprigs fresh parsley (for garnish),",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 pinch dried oregano,",
    )
    recipe3.ID = 3
    recipe3.Yield = 2

    //call to printRecipe function below
    printRecipe(recipe1)
    totalTime(recipe1)
    printRecipe(recipe2)
    totalTime(recipe2)
    printRecipe(recipe3)
    totalTime(recipe3)
}

//function to print the winner for recipe of the day to use
//for either lunch or dinner
func printRecipeOfTheDay(recipe Recipe) {
    fmt.Printf("The recipe of the day is : %s\n", recipe.name)
}

Answer 1

您的陈述顺序错误。当您尝试打印配方时，您已经声明了它，但是您没有进行初始化，所以它应该为空。

package main

import (
    "fmt"
    "math/rand"
    "time"
)

//Struct for Recipe below
type Recipe struct { //Struct for recipe information
    name        string
    prepTime    int
    cookTime    int
    Ingredients []string //this is now a slice that will accept multiple elements
    ID          int
    Yield       int
}

//function to print Recipe
func printRecipe(recipe Recipe) {
    fmt.Printf("Recipe Name : %s\n", recipe.name)
    fmt.Printf("Prep Time : %d\n", recipe.prepTime)
    fmt.Printf("Cook Time : %d\n", recipe.cookTime)
    fmt.Printf("Ingredients : %s\n", recipe.Ingredients)
    fmt.Printf("Recipe ID : %d\n", recipe.ID)
}

//Returns total time by addings cookTime and prepTime
func totalTime(recipe Recipe) {
    fmt.Printf("The total time for this recipe is %d\n", recipe.cookTime+recipe.prepTime)
}

func main() {
    var recipe1 Recipe //Declare recipe1 of Type Recipe
    var recipe2 Recipe
    var recipe3 Recipe


        /* recipe1 specifications */
    recipe1.name = "BBQ Pulled Chicken"
    recipe1.prepTime = 25
    recipe1.cookTime = 5
    recipe1.Ingredients = append(
        recipe1.Ingredients,
        "1 8-ounce can reduced-sodium tomato sauce",
    )
    recipe1.Ingredients = append(
        recipe1.Ingredients,
        "1/2 medium onion (grated),",
    )
    recipe1.ID = 1
    recipe1.Yield = 8

    /* Recipe 2 specifications */

    recipe2.name = "Steak Tacos with Pineapple"
    recipe2.prepTime = 45
    recipe2.cookTime = 45
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "3 tablespoons soy sauce,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 tablespoon finely grated garlic,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 tablespoon finely grated peeled fresh ginger,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 1/2 pounds skirt steak, cut into 5-inch lengths,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "Salt",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "Pepper",
    )
    recipe2.ID = 2
    recipe2.Yield = 4

    recipe3.name = "Simple Lemon Herb Chicken"
    recipe3.prepTime = 10
    recipe3.cookTime = 15
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "2 skinless boneless chicken breast halves,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 Lemon,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "Salt and Pepper to taste,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 tablespoon olive oil,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "2 sprigs fresh parsley (for garnish),",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 pinch dried oregano,",
    )
    recipe3.ID = 3
    recipe3.Yield = 2

    //choose random number for recipe
    r := rand.New(rand.NewSource(time.Now().UnixNano()))
    i := r.Perm(5)
    fmt.Printf("%v\n", i)
    fmt.Printf("%d\n", i[0])

    //assign slices of int from Perm to variables assigned days of the week
    var monday = i[0]
    var tuesday = i[1]
    var wednesday = i[2]
    var thursday = i[3]
    var friday = i[4]

    //testing printing of variables assigned to days
    fmt.Printf("This is for the day Monday %d\n", monday)
    fmt.Printf("%d\n", tuesday)
    fmt.Printf("%d\n", wednesday)
    fmt.Printf("%d\n", thursday)
    fmt.Printf("%d\n", friday)

    //logic for Mondays Recipe
    if monday == 0 {
        fmt.Println(0)
        printRecipeOfTheDay(recipe1)
    } else if monday == 1 {
        fmt.Println(1)
        printRecipeOfTheDay(recipe2)
    } else if monday == 2 {
        fmt.Println(2)
        printRecipeOfTheDay(recipe3)
    } else if monday == 3 {
        fmt.Println(3)
    }

    //call to printRecipe function below
    printRecipe(recipe1)
    totalTime(recipe1)
    printRecipe(recipe2)
    totalTime(recipe2)
    printRecipe(recipe3)
    totalTime(recipe3)
}

//function to print the winner for recipe of the day to use
//for either lunch or dinner
func printRecipeOfTheDay(recipe Recipe) {
    fmt.Printf("The recipe of the day is : %s\n", recipe.name)
}

我只是快速剪切并粘贴，因为我现在很忙。我可以稍后编辑它，它只是为了风格和可读性。我建议使用initRecipes方法并让它返回[]Recipe并使用复合文字语法进行初始化，而不是一遍又一遍地调用append。

Answer 2

感谢您的建议我修改了我的代码，它位于下方。它按预期工作。现在我只需要清理它了

package main

import (
    "fmt"
    "math/rand"
    "time"
)

//Struct for Recipe below
type Recipe struct { //Struct for recipe information
    name        string
    prepTime    int
    cookTime    int
    Ingredients []string //this is now a slice that will accept multiple elements
    ID          int
    Yield       int
}

//main method
func main() {
    //5 variables below for 5 recipes for Monday-Friday
    var recipe1 Recipe //Declare recipe1 of Type Recipe
    var recipe2 Recipe
    var recipe3 Recipe
    var recipe4 Recipe
    var recipe5 Recipe

    //choose random number for recipe
    r := rand.New(rand.NewSource(time.Now().UnixNano()))
    i := r.Perm(5)
    fmt.Printf("%v\n", i)
    fmt.Printf("%d\n", i[0])
    fmt.Printf("%d\n", i[1])

    //assign slices of int from Perm to variables assigned days of the week
    var monday = i[0]
    var tuesday = i[1]
    var wednesday = i[2]
    var thursday = i[3]
    var friday = i[4]

    //testing printing of variables assigned to days
    fmt.Printf("This is for the day Monday %d\n", monday)
    fmt.Printf("This is for the day Tuesday %d\n", tuesday)
    fmt.Printf("This is for the day Wednesday %d\n", wednesday)
    fmt.Printf("This is for the day Thursday %d\n", thursday)
    fmt.Printf("This is for the day Friday %d\n", friday)

    /* recipe1 specifications */
    recipe1.name = "BBQ Pulled Chicken"
    recipe1.prepTime = 25
    recipe1.cookTime = 5
    recipe1.Ingredients = append(
        recipe1.Ingredients,
        "1 8-ounce can reduced-sodium tomato sauce",
    )
    recipe1.Ingredients = append(
        recipe1.Ingredients,
        "1/2 medium onion (grated),",
    )
    recipe1.ID = 1
    recipe1.Yield = 8

    /* Recipe 2 specifications */

    recipe2.name = "Steak Tacos with Pineapple"
    recipe2.prepTime = 45
    recipe2.cookTime = 45
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "3 tablespoons soy sauce,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 tablespoon finely grated garlic,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 tablespoon finely grated peeled fresh ginger,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "1 1/2 pounds skirt steak, cut into 5-inch lengths,",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "Salt",
    )
    recipe2.Ingredients = append(
        recipe2.Ingredients,
        "Pepper",
    )
    recipe2.ID = 2
    recipe2.Yield = 4

    recipe3.name = "Simple Lemon Herb Chicken"
    recipe3.prepTime = 10
    recipe3.cookTime = 15
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "2 skinless boneless chicken breast halves,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 Lemon,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "Salt and Pepper to taste,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 tablespoon olive oil,",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "2 sprigs fresh parsley (for garnish),",
    )
    recipe3.Ingredients = append(
        recipe3.Ingredients,
        "1 pinch dried oregano,",
    )
    recipe3.ID = 3
    recipe3.Yield = 2

    //recipe4 specifications
    recipe4.name = "Easy Meatloaf"
    recipe4.prepTime = 10
    recipe4.cookTime = 60
    recipe4.Ingredients = append(
        recipe4.Ingredients,
        "1 onion (chopped),",
    )
    recipe4.Ingredients = append(
        recipe4.Ingredients,
        "1 cup milk,",
    )
    recipe4.Ingredients = append(
        recipe4.Ingredients,
        "1 cup dried bread crumbs,",
    )
    recipe4.ID = 4
    recipe4.Yield = 8

    //recipe 5 specifications
    recipe5.name = "Fast Salmon with a Ginger Glaze"
    recipe5.prepTime = 5
    recipe5.cookTime = 20
    recipe5.Ingredients = append(
        recipe5.Ingredients,
        "salt to taste,",
    )
    recipe5.Ingredients = append(
        recipe5.Ingredients,
        "1/3 cup cold water,",
    )
    recipe5.Ingredients = append(
        recipe5.Ingredients,
        "1/4 cup seasoned rice vinegar,",
    )
    recipe5.ID = 5
    recipe5.Yield = 4

    //call to printRecipe function below
    printRecipe(recipe1)
    totalTime(recipe1)
    printRecipe(recipe2)
    totalTime(recipe2)
    printRecipe(recipe3)
    totalTime(recipe3)
    printRecipe(recipe4)
    totalTime(recipe4)
    printRecipe(recipe5)
    totalTime(recipe5)

    //logic for Mondays Recipe
    if monday == 0 {
        fmt.Println(0)
        printRecipeOfTheDay(recipe1)
    } else if monday == 1 {
        fmt.Println(1)
        printRecipeOfTheDay(recipe2)
    } else if monday == 2 {
        fmt.Println(2)
        printRecipeOfTheDay(recipe3)
    } else if monday == 3 {
        fmt.Println(3)
        printRecipeOfTheDay(recipe4)
    } else if monday == 4 {
        fmt.Println(4)
        printRecipeOfTheDay(recipe5)
    }

    //logic for Tuesdays Recipe
    if tuesday == 0 {
        fmt.Println(0)
        printRecipeOfTheDay(recipe1)
    } else if tuesday == 1 {
        fmt.Println(1)
        printRecipeOfTheDay(recipe2)
    } else if tuesday == 2 {
        fmt.Println(2)
        printRecipeOfTheDay(recipe3)
    } else if tuesday == 3 {
        fmt.Println(3)
        printRecipeOfTheDay(recipe4)
    } else if tuesday == 4 {
        fmt.Println(4)
        printRecipeOfTheDay(recipe5)
    }
}

//function to print Recipe
func printRecipe(recipe Recipe) {
    fmt.Printf("Recipe Name : %s\n", recipe.name)
    fmt.Printf("Prep Time : %d\n", recipe.prepTime)
    fmt.Printf("Cook Time : %d\n", recipe.cookTime)
    fmt.Printf("Ingredients : %s\n", recipe.Ingredients)
    fmt.Printf("Recipe ID : %d\n", recipe.ID)
}

//Returns total time by addings cookTime and prepTime
func totalTime(recipe Recipe) {
    fmt.Printf("The total time for this recipe is %d\n", recipe.cookTime+recipe.prepTime)
}

//function to print the winner for recipe of the day to use
//for either lunch or dinner
func printRecipeOfTheDay(recipe Recipe) {
    fmt.Printf("The recipe of the day is : %s\n", recipe.name)
}

Go Program不显示分配给变量的Sliced Int的所需结果

2 个答案: