slice

I have a sized byte array that I got after doing md5.Sum() . data := []byte("testing") var pass string var b [16]byte b = md5.Sum(data) pass = string(b) The error: cannot convert b (type [16]byte) to type string I find the solution at this problem Change to: pass = string(b[:]) But why can not use it like this? pass = string(b) Short answer is because the Go Language Specification does not permit it. Quoting from the Go Language Specification: Conversions : A non-constant value x can be converted to type T in any of these cases: x is assignable to T . x 's type and T have identical underlying

I was trying to understand what is the difference between spread syntax vs slice method in the following approach. suppose I want to make an actual copy of an array, I can probably easily do it using spread syntax var fruits = ["Banana", "Chips" , "Orange", "Lemon", "Apple", "Mango"] var newCitrus = [...fruits] If I console.log this ["Banana", "Chips", "Orange", "Lemon", "Apple", "Mango"] but I can also create a copy of an array using the slice method. Considering the same array above, if I do something like this... var citrus = fruits.slice(0); and then console log it, it will give me exactly

数组与切片 定义数组 var score [5]float64 //四种初始化数组方式 var numArr01 [3]int = [3]int{1,2,3} var numArr02 = [3]int{4,5,6} var numArr03 = [...]int{8,9,10} var numArr04 = [...]int{1:800, 2:900, 3:999} //类型推导 strArr05 := [...]string{1:"tom", 0:"jack", 8:"aim"} 数组的遍历 常规遍历 略 for-range结构遍历 go语言独有的一种结构 for index, value := range arry01 {...} 第一个参数是下标，第二个是值，可用占位符_代替 都为局部变量 index和value不是固定的，可自己取名，一般这样写 数组注意事项 数组是多种数据类型的组合，一旦声明，长度固定，不能动态变化 数组中的元素可以是任意类型，包括引用类型，但是不能混用 没有赋值为默认值 数组下标必须在指定范围内使用，否则会报panic错误，数组越界 若想在其他函数中修改，可以使用引用传递（指针方式） 长度是数组的一部分,传递时需考虑长度，所以不能：arr[4]=arr[3],也不能：arr[]=arr[3] 切片介绍 引用类型，遵循引用类型传递机制 动态变化的数组

Let's say I have the following array of ints of length 3: nums := [3]int{1,2,3} Then I grab the slice of just the first two items numSlice := nums[:2] Invoking cap on numSlice and nums yields 3 in both cases, and len yields 2 and 3 respectively. If I then append to that slice ( numSlice = append(numSlice, 10) ), the underlying array ( nums ) is now [1 2 10] . cap remains at 3 for both, as the underlying array of the slice is the same, and len for the slice is now 3. However, if I append to that slice again ( numSlice = append(numSlice, 20) ), the underlying array of the slice must change - we

Is there any way in python to use a tuple as the indices for a slice? The following is not valid: >>> a = range(20) >>> b = (5, 12) # my slice indices >>> a[b] # not valid >>> a[slice(b)] # not valid >>> a[b[0]:b[1]] # is an awkward syntax [5, 6, 7, 8, 9, 10, 11] >>> b1, b2 = b >>> a[b1:b2] # looks a bit cleaner [5, 6, 7, 8, 9, 10, 11] It seems like a reasonably pythonic syntax so I am surprised that I can't do it. (update) And the solution turns out to be: >>> a[slice(*b)] [5, 6, 7, 8, 9, 10, 11] You can use Python's *args syntax for this: >>> a = range(20) >>> b = (5, 12) >>> a[slice(*b)] [5