make和new都是用来分配内存的。相比make，new的使用场景很少。面试经常被问，来看看这两个具体什么区别
new
// The new built-in function allocates memory. The first argument is a type,
// not a value, and the value returned is a pointer to a newly
// allocated zero value of that type.
func new(Type) *Type
从函数原型可以看出，new接收一个参数，可以是任意类型，返回的是该类型的指针。输出看下
func main() {
a := new([]int)
fmt.Printf("%T %p\n", a, a)
}
结果：
*[]int 0xc000004480
a的类型是我们传入的 []int 类型的指针 *[]int
0xc000004480是该指针的地址
不会进行初始化，new完的map不能直接使用，会panic
new会将类型置为零值
make
// The make built-in function allocates and initializes an object of type
// slice, map, or chan (only). Like new, the first argument is a type, not a
// value. Unlike new, make's return type is the same as the type of its
// argument, not a pointer to it. The specification of the result depends on
// the type:
// Slice: The size specifies the length. The capacity of the slice is
// equal to its length. A second integer argument may be provided to
// specify a different capacity; it must be no smaller than the
// length. For example, make([]int, 0, 10) allocates an underlying array
// of size 10 and returns a slice of length 0 and capacity 10 that is
// backed by this underlying array.
// Map: An empty map is allocated with enough space to hold the
// specified number of elements. The size may be omitted, in which case
// a small starting size is allocated.
// Channel: The channel's buffer is initialized with the specified
// buffer capacity. If zero, or the size is omitted, the channel is
// unbuffered.
func make(t Type, size ...IntegerType) Type
看函数的原型，第一个参数是类型，看注释，类型仅支持 map、slice、channel。
第二个参数是大小。
func main() {
//a := new([]int)
//fmt.Printf("%T %p\n", a, a)
var a map[int]int
a = make(map[int]int, 8)
var b []int
b = make([]int, 8)
fmt.Println(len(b), cap(b), b)
fmt.Printf("%T %v %v\n", a, a, len(a))
c := make(chan int,5)
fmt.Println(c, len(c))
}
结果
map[int]int map[] 0
8 8 [0 0 0 0 0 0 0 0]
0xc000076000 0
初始化完成后，类型是传入类型对应的一个实例。
对于第二个参数 size，对于slice，传入的参数初始化完成后参数对应的是切片的 len和cap 均为size，并且切片中得值初始化为零值
对于map，size为 map 的大小
对于channel，不指定size的，表示该channel为无缓冲的channel，指定了大小的，表示该channel 为有缓冲的channel
总结
make仅仅能用于初始化 map、slice、channel。而且对于map和channel，必须初始化之后才能使用否则会报错
map未初始化
panic: assignment to entry in nil map
goroutine 1 [running]:
main.main()
channel 未初始化
fatal error: all goroutines are asleep - deadlock!
goroutine 1 [chan receive (nil chan)]:
main.main()
new 仅仅是为对应类型申请一片内存空间，然后返回该内存对应的指针