1.语法老在变,第一个是0.3版文档中的例子,{}表示向量语法已经废弃,第2个是0.6版文档的例子,在0.5版中是无效的,只有0.51自带文档中的例子可以执行。
julia> for T = {Int8,Int16,Int32,Int64,Int128,Uint8,Uint16,Uint32,Uint64,Uint128} println("$(lpad(T,7)): [$(typemin(T)),$(typemax(T))]") end ERROR: syntax: { } vector syntax is discontinued julia> for T = [Int8,Int16,Int32,Int64,Int128,Uint8,Uint16,Uint32,Uint64,Uint128] println("$(lpad(T,7)): [$(typemin(T)),$(typemax(T))]") end ERROR: UndefVarError: Uint8 not defined in anonymous at .\:? julia> for T in [Int8,Int16,Int32,Int64,Int128,UInt8,UInt16,UInt32,UInt64,UInt128] println("$(lpad(T,7)): [$(typemin(T)),$(typemax(T))]") end Int8: [-128,127] Int16: [-32768,32767] Int32: [-2147483648,2147483647] Int64: [-9223372036854775808,9223372036854775807] Int128: [-170141183460469231731687303715884105728,170141183460469231731687303715884105727] UInt8: [0,255] UInt16: [0,65535] UInt32: [0,4294967295] UInt64: [0,18446744073709551615] UInt128: [0,340282366920938463463374607431768211455] julia> x =Int128(2)^Int128(3)^Int128(4) 2417851639229258349412352
2.测试程序用时
julia> @elapsed [x for x in 1:10^6]; julia> @elapsed [x for x in 1:10^6] 0.151227431 julia> @elapsed [x for x in 1:10^7] 0.179493186 julia> @timed [x for x in 1:10^7] ([1,2,3,4,5,6,7,8,9,10 … 9999991,9999992,9999993,9999994,9999995,9999996,9999 997,9999998,9999999,10000000],0.147096148,40360520,0.098642467,Base.GC_Diff(4036 0520,1,0,12060,0,0,98642467,1,1)) julia> @time [x for x in 1:10^7] 0.175094 seconds (12.06 k allocations: 38.491 MB, 57.12% gc time) 10000000-element Array{Int32,1}: 1 2 3 4 5 6 7 8 9 10 ⋮ 9999991 9999992 9999993 9999994 9999995 9999996 9999997 9999998 9999999 10000000 julia> tic(); [x for x in 1:10^7];toc() elapsed time: 0.193216436 seconds 0.193216436 julia> tic(); [x for x in 1:10^7];toq() 0.070731702
3.二进制位的显示
julia> x =Int128(2)^Int128(3)^Int128(4) 2417851639229258349412352 julia> bits(x) "00000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000 000000000" julia> bits(3.14) "0100000000001001000111101011100001010001111010111000010100011111" julia> bits(Float64(3.14)) "0100000000001001000111101011100001010001111010111000010100011111" julia> bits(Float32(3.14)) "01000000010010001111010111000011" julia> bits(Float16(3.14)) "0100001001001000"