基本数据类型 #

一、整数类型 #

1.1 整数类型列表 #

类型	位数	范围
`Int8`	8位	-128 到 127
`Int16`	16位	-32768 到 32767
`Int32`	32位	-2147483648 到 2147483647
`Int64`	64位	-9223372036854775808 到 9223372036854775807
`UInt8`	8位	0 到 255
`UInt16`	16位	0 到 65535
`UInt32`	32位	0 到 4294967295
`UInt64`	64位	0 到 18446744073709551615
`Int`	平台相关	平台字长

1.2 整数定义 #

mojo

def main():
    let small: Int8 = 127
    let medium: Int32 = 2147483647
    let large: Int64 = 9223372036854775807
    
    let unsigned_small: UInt8 = 255
    let unsigned_large: UInt64 = 18446744073709551615
    
    print(small, medium, large)

main()

1.3 整数字面量 #

mojo

def main():
    let decimal = 42
    let hex = 0x2A
    let binary = 0b101010
    let octal = 0o52
    
    print(decimal)
    print(hex)
    print(binary)
    print(octal)

main()

1.4 整数运算 #

mojo

def main():
    let a: Int = 10
    let b: Int = 3
    
    print(a + b)
    print(a - b)
    print(a * b)
    print(a // b)
    print(a % b)

main()

1.5 溢出处理 #

mojo

def main():
    var x: Int8 = 127
    x = x + 1

main()

二、浮点数类型 #

2.1 浮点类型列表 #

类型	位数	精度
`Float16`	16位	半精度
`Float32`	32位	单精度
`Float64`	64位	双精度

2.2 浮点数定义 #

mojo

def main():
    let single: Float32 = 3.14159
    let double: Float64 = 3.14159265358979
    
    print(single)
    print(double)

main()

2.3 科学计数法 #

mojo

def main():
    let large = 1.5e10
    let small = 1.5e-10
    
    print(large)
    print(small)

main()

2.4 特殊浮点值 #

mojo

def main():
    let inf = Float64("inf")
    let neg_inf = Float64("-inf")
    let nan = Float64("nan")
    
    print(inf)
    print(neg_inf)
    print(nan)

main()

2.5 浮点运算 #

mojo

def main():
    let a: Float64 = 10.0
    let b: Float64 = 3.0
    
    print(a + b)
    print(a - b)
    print(a * b)
    print(a / b)

main()

三、布尔类型 #

3.1 布尔值定义 #

mojo

def main():
    let is_true: Bool = True
    let is_false: Bool = False
    
    print(is_true)
    print(is_false)

main()

3.2 布尔运算 #

mojo

def main():
    let a = True
    let b = False
    
    print(a and b)
    print(a or b)
    print(not a)

main()

3.3 比较结果 #

mojo

def main():
    let x = 10
    let y = 20
    
    let result1 = x < y
    let result2 = x == y
    let result3 = x >= y
    
    print(result1)
    print(result2)
    print(result3)

main()

3.4 布尔转换 #

mojo

def main():
    let num = 0
    let bool_val = Bool(num)
    
    print(bool_val)

main()

四、字符类型 #

4.1 字符定义 #

mojo

def main():
    let letter: String = 'A'
    let digit: String = '7'
    let symbol: String = '@'
    
    print(letter)
    print(digit)
    print(symbol)

main()

4.2 转义字符 #

转义序列	描述
`\n`	换行
`\t`	制表符
`\\`	反斜杠
`\'`	单引号
`\"`	双引号
`\r`	回车

mojo

def main():
    print("Hello\nWorld")
    print("Tab\there")
    print("Quote: \"test\"")

main()

五、类型转换 #

5.1 显式转换 #

mojo

def main():
    let int_val: Int = 42
    let float_val: Float64 = Float64(int_val)
    let str_val: String = String(int_val)
    
    print(int_val)
    print(float_val)
    print(str_val)

main()

5.2 数值类型转换 #

mojo

def main():
    let small: Int8 = 100
    let large: Int64 = Int64(small)
    
    let float_val: Float64 = 3.7
    let int_val: Int = Int(float_val)
    
    print(large)
    print(int_val)

main()

5.3 字符串转数值 #

mojo

def main():
    let str_num = "12345"
    let int_val = Int(str_num)
    
    let str_float = "3.14159"
    let float_val = Float64(str_float)
    
    print(int_val)
    print(float_val)

main()

六、类型推断 #

6.1 字面量推断 #

mojo

def main():
    let int_val = 42
    let float_val = 3.14
    let bool_val = True
    let str_val = "Hello"

main()

6.2 上下文推断 #

mojo

fn process(value: Float64):
    print(value)

def main():
    process(42)

main()

七、类型别名 #

7.1 定义类型别名 #

mojo

alias UserID = Int64
alias Price = Float64

def main():
    let user_id: UserID = 12345
    let price: Price = 99.99
    
    print(user_id)
    print(price)

main()

7.2 泛型类型别名 #

mojo

alias Vector3 = SIMD[DType.float64, 3]

def main():
    let v = Vector3(1.0, 2.0, 3.0)
    print(v)

main()

八、SIMD类型 #

8.1 SIMD基础 #

mojo

from SIMD import SIMD

def main():
    let v = SIMD[DType.float64, 4](1.0, 2.0, 3.0, 4.0)
    print(v)

main()

8.2 SIMD运算 #

mojo

from SIMD import SIMD

def main():
    let a = SIMD[DType.float64, 4](1.0, 2.0, 3.0, 4.0)
    let b = SIMD[DType.float64, 4](5.0, 6.0, 7.0, 8.0)
    
    let sum = a + b
    let product = a * b
    
    print(sum)
    print(product)

main()

九、总结 #

本章学习了：

整数类型及其范围
浮点数类型及精度
布尔类型
字符类型
类型转换
类型推断
SIMD类型

下一章，我们将学习字符串类型。