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Split a string by separator rule (string.split)

Declaration​

parts = string.split(text, sep)

Parameters​

  • text
    string. Text to split.
  • sep
    string. Separator string.

Returns​

  • parts
    table. Array of split segments in order.

Description​

Split a string by a separator rule.
Keywords: split string, split text.

Examples​

-- Example 1 (split account/password):
t = string.split('lfue6841214----123456', '----')
sys.alert('Account: '..t[1])
--
-- Example 2 (get text between two # marks):
t = string.split('您好，验证码是#4937#，15分钟内有效。【爆炸科技】', '#')
sys.alert('Code: '..t[2])
--
-- Example 3 (a more complex middle extraction):
t = string.split('您好，验证码是4937，15分钟内有效。【爆炸科技】', '验证码是')
t = string.split(t[2], '，15分钟')
sys.alert('Code: '..t[1])

Note: Uses function outside of this chapter: sys.alert

Wrapper example 1​

-- Extract middle text (return nil if not found)
function str_middle(str, sep1, sep2)
    assert(type(str) == 'string', '`str_middle` #1 must be string')
    assert(type(sep1) == 'string', '`str_middle` #2 must be string')
    assert(type(sep2) == 'nil' or type(sep2) == 'string', '`str_middle` #3 optional but must be string')
    local t = string.split(str, sep1)
    if not sep2 or sep1==sep2 then
        return t[2]
    else
        if t[2] == nil then
            return nil
        else
            t = string.split(t[2], sep2)
            if t[2] == nil then
                return nil
            else
                return t[1]
            end
        end
    end
end
--
r = str_middle('您好，验证码是4937，15分钟内有效。【爆炸科技】', '码是', '，15分')
sys.alert('Code: '..r)
-- "4937"
--
r = str_middle('您好，验证码是#8346#，15分钟内有效。【爆炸科技】', '#')
sys.alert('Code: '..r)
-- "8346"

Note: Uses function outside of this chapter: sys.alert

Wrapper example 2​

-- basename
function str_strip_dirname(path)
    local d = string.split(path, '/')
    return d[#d]
end

-- dirname
function str_strip_filename(path)
    local d = string.split(path, '/')
    d[#d] = nil
    return table.concat(d, '/')
end

-- strip extension of last path segment
function str_strip_extension(path)
    local d = string.split(path, '/')
    local fnt = string.split(d[#d], '.')
    d[#d] = fnt[1]
    return table.concat(d, '/')
end

-- get extension(s) of last path segment
function str_get_extension(path)
    local d = string.split(path, '/')
    local fnt = string.split(d[#d], '.')
    table.remove(fnt, 1)
    return table.concat(fnt, '.')
end

sys.alert(str_strip_dirname("/private/var/mobile/Media/1ferver/lua/scripts/1.lua.xxt"))
-- "1.lua.xxt"

sys.alert(str_strip_filename("/private/var/mobile/Media/1ferver/lua/scripts/1.lua.xxt"))
-- "/private/var/mobile/Media/1ferver/lua/scripts"

sys.alert(str_strip_extension("/private/var/mobile/Media/1ferver/lua/scripts/1.lua.xxt"))
-- "/private/var/mobile/Media/1ferver/lua/scripts/1"

sys.alert(str_get_extension("/private/var/mobile/Media/1ferver/lua/scripts/1.lua.xxt"))
-- "lua.xxt"

sys.alert(str_strip_extension(str_strip_dirname("/private/var/mobile/Media/1ferver/lua/scripts/1.lua.xxt")))
-- "1"

Note: Uses functions outside of this chapter: sys.alert, table.concat

-- Not an example using string.split
function text_explode(text)
    local ret = {}
    for p, c in utf8.codes(text) do
        ret[#ret + 1] = utf8.char(c)
    end
    return ret
end
--
local t = text_explode('你好，XXTouch')
sys.alert(table.concat(t, '/')) -- "你/好/，/X/X/T/o/u/c/h"

Note: Uses functions outside of this chapter: sys.alert, table.concat, utf8.char, utf8.codes

More examples​

At the end of this chapter