Angular - 将HTTP发布数据发送到服务器[HOW TO](Angular - send HTTP post data to server [HOW TO])

 
 
 片 
 
 
 对于字符串，数组，指向数组的指针或切片a，主表达式 
 
 
 a [低：高] 
 
 
 构造子串或切片。 索引表达式低和高选择哪些元素出现在结果中。 结果索引从0开始，长度等于high - low。 
 
 
 对于数组或字符串，索引低和高必须满足0 <=低<=高<=长度; 对于切片，上限是容量而不是长度。 
 
 
 索引 
 
 
 表单的主要表达 
 
 
 斧头] 
 
 
 表示由x索引的数组，切片，字符串或映射的元素。 值x分别称为索引或映射键。 以下规则适用： 
 
 
 对于类型A或* A，其中A是数组类型，或者对于类型S，其中S是切片类型： 
 
 
x must be an integer value and 0 <= x < len(a)

a[x] is the array element at index x and the type of a[x] is
the element type of A

if a is nil or if the index x is out of range, a run-time panic occurs
 
 
 制作切片，地图和频道 
 
 
make(T, n)       slice      slice of type T with length n and capacity n
make(T, n, m)    slice      slice of type T with length n and capacity m
 
 
 y必须是整数值且0 <= y <len（pixel [] uint8）。 x必须是整数值且0 <= x <len（pixel [] [] uint8）。 例如， 
 
package main

import "tour/pic"

func Pic(dx, dy int) [][]uint8 {
    pixels := make([][]uint8, dy)
    for y := 0; y < dy; y++ {
        pixels[y] = make([]uint8, dx)
        for x := 0; x < dx; x++ {
            pixels[y][x] = uint8(x * y)
        }
    }
    return pixels
}

func main() {
    pic.Show(Pic)
}

 
 
Slices
 
 
For a string, array, pointer to array, or slice a, the primary expression
 
 
a[low : high]
 
 
constructs a substring or slice. The index expressions low and high select which elements appear in the result. The result has indexes starting at 0 and length equal to high - low. 
 
 
For arrays or strings, the indexes low and high must satisfy 0 <= low <= high <= length; for slices, the upper bound is the capacity rather than the length.
 
 
Indexes
 
 
A primary expression of the form
 
 
a[x]
 
 
denotes the element of the array, slice, string or map a indexed by x. The value x is called the index or map key, respectively. The following rules apply:
 
 
For a of type A or *A where A is an array type, or for a of type S where S is a slice type:
 
 
x must be an integer value and 0 <= x < len(a)

a[x] is the array element at index x and the type of a[x] is
the element type of A

if a is nil or if the index x is out of range, a run-time panic occurs
 
 
Making slices, maps and channels
 
 
make(T, n)       slice      slice of type T with length n and capacity n
make(T, n, m)    slice      slice of type T with length n and capacity m
 
 
y must be an integer value and 0 <= y < len(pixel[]uint8). x must be an integer value and 0 <= x < len(pixel[][]uint8). For example,
 
package main

import "tour/pic"

func Pic(dx, dy int) [][]uint8 {
    pixels := make([][]uint8, dy)
    for y := 0; y < dy; y++ {
        pixels[y] = make([]uint8, dx)
        for x := 0; x < dx; x++ {
            pixels[y][x] = uint8(x * y)
        }
    }
    return pixels
}

func main() {
    pic.Show(Pic)
}