for 循环

• OC 风格的循环

var sum = 0
for var i = 0; i < 10; i++ {
    sum += i
}
print(sum)

• for-in，0..<10 表示从0到9

sum = 0
for i in 0..<10 {
    sum += i
}
print(sum)

• 范围 0...10 表示从0到10

sum = 0
for i in 0...10 {
    sum += i
}
print(sum)

• 省略下标
  • _ 能够匹配任意类型
  • _ 表示忽略对应位置的值

for _ in 0...10 {
    print("hello")
}