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Javascript 的 eval() 語法

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Javascript 的 eval() 語法

eval() 是一個相當有趣、強大、不容易理解的函式,但功用實在太強,撰寫 Javascript 時經常會使用到。

eval 是 evaluates 的簡寫,是用來將「一句話」執出來。例如:

var n=3;
var b=5,c=6;
eval('a'+n+'=b*c');

上例,在 eval() 中的字串,展開變成

a3=b*c

沒錯,結果就是 a3=b*c,也就是變數 a3 的結果為 30。

由上例可知,eval() 是把一串字串,當作指令來執行,並得出結果。

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2009-04-22T15:34:48+0000


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