字符串插值

Lua:
字符串插值

How to: (如何操作：)

Lua doesn’t have built-in string interpolation, but we can get the job done nicely with some creativity. Here’s how:

-- Using string.format
local name = "Xiao Ming"
local age = 25
local greeting = string.format("Hello, %s! You are %d years old.", name, age)
print(greeting)  -- Output: Hello, Xiao Ming! You are 25 years old.

You can also concatenate strings directly:

-- Direct concatenation
local greeting = "Hello, " .. name .. "! You are " .. age .. " years old."
print(greeting)  -- Same output as above

Deep Dive (深入了解)

Historically, Lua never aimed for string interpolation within the language itself, and that’s partly why string.format is the go-to option—it supports a variety of formats, following the C printf style.

However, there are some makeshift alternatives:

Using the gsub function:

local template = "Hello, ${name}! You are ${age} years old."
local interpolated = template:gsub('%${(%w+)}', {name="Xiao Ming", age=25})
print(interpolated)  -- Output mirrors the above

Custom interpolation function:

function interpolate(s, tab)
  return (s:gsub('($%b{})', function(w) return tab[w:sub(3, -2)] or w end))
end

local message = interpolate("Hello, ${name}! You are ${age} years old.", {name="Xiao Ming", age=25})
print(message)  -- Identical to previous results

Each method has its pros and cons, including readability and performance implications. Choose based on your need for speed or clarity.

Lua:字符串插值

How to: (如何操作：)

Deep Dive (深入了解)

See Also (另请参阅)

Lua:
字符串插值