考虑Octave/Matlab中的以下两个函数; 他们之间的唯一区别是身体中的线条是否以分号结尾:
function [a, b, c] = fooNoSemicolons (x, y, z)
a = x * 42
b = y + 42
c = (x * y) / (z * 42)
endfunction
function [a, b, c] = fooSemicolons (x, y, z)
a = x * 42;
b = y + 42;
c = (x * y) / (z * 42);
endfunction
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现在考虑以下调用及其输出:
fprintf ("no semicolons: \n"); disp (fooNoSemicolons (12, 13, 14));
fprintf ("done\n");
fprintf ("semicolons: \n"); disp (fooSemicolons (12, 13, 14));
fprintf ("done\n");
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Run Code Online (Sandbox Code Playgroud)no semicolons: a = 504 b = 55 c = 0.26531 504 done semicolons: 504 done
很明显,两个函数都产生相同的答案,即a的值,即504,但我不太清楚内部是否存在语义上的差异.
我无法在Matlab/Octave中找到有关分号含义的文档,但我做了一些不太明白的实验:
fprintf ("noSemicolons: \n");
[someA, someB, someC] = fooNoSemicolons (12, 13, 14);
fprintf ("done\n");
disp ([someA, someB, someC]);
fprintf ("semicolons:\n");
[moreA, moreB, moreC] = fooSemicolons (12, 13, 14);
fprintf ("done\n");
disp ([moreA, moreB, moreC]);
fprintf ("noSemicolons: \n");
otherStuff = fooNoSemicolons (12, 13, 14);
% otherStuff apparently does not get bound to an array or vector!
disp (otherStuff);
fprintf ("done\n");
fprintf ("semicolons:\n");
moreStuff = fooSemicolons (12, 13, 14);
% moreStuff apparently does not get bound to an array or vector!
fprintf ("done\n");
disp (moreStuff);
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Run Code Online (Sandbox Code Playgroud)noSemicolons: a = 504 b = 55 c = 0.26531 done 504.00000 55.00000 0.26531 semicolons: done 504.00000 55.00000 0.26531 noSemicolons: a = 504 b = 55 c = 0.26531 504 done semicolons: done 504
在Matlab/Octave代码行末尾加一个分号可防止控制台打印答案/变量赋值/等等.
x=5
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将x设置为5并打印x的值.
x=5;
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将x设置为5.
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