您好,登錄后才能下訂單哦!
小編給大家分享一下dim函數(shù)第三個參數(shù)如何設(shè)置截取字符的長度,相信大部分人都還不怎么了解,因此分享這篇文章給大家參考一下,希望大家閱讀完這篇文章后大有收獲,下面讓我們一起去了解一下吧!
dim函數(shù)的第三個參數(shù),也就是截取字符的長度,我在設(shè)置這個的時候,出了些問題:response.write mid(up_address,a(i),a(i+1)-1) & “<br />”像我上面這樣寫的時候,它就會報錯,提示無效的過程調(diào)用或參數(shù),
response.write mid(up_address,a(i),a(i+1)+1) & “<br />”但是當(dāng)我把其中的a(i+1)-1改為a(i+1)+1時,就能執(zhí)行了,a(i+1)對應(yīng)的值是11,可為什么只能減不能加呢?全部代碼如下:
VB code:
復(fù)制代碼 代碼如下:
dim a(),up_address
up_address = "aaa djaldk adflj adafadfasdfa afd ad"
redim a(len(up_address))
a(0) = instr(up_address," ")
response.write a(0) & "<br />"
if a(0)<>0 then
for i=0 to len(up_address)-1
a(i+1) = instr(a(i)+1,up_address," ")
response.write mid(up_address,a(i),a(i+1)-1) & "<br />"
if a(i+1)=0 then
exit for
end if
response.write a(i+1) & "<br />"
next
end if如上代碼,我是想把字符串按空格分解出來,但是mid的第三個參數(shù)那出了點問題,我本來是想這樣截取的:
VB code:
復(fù)制代碼 代碼如下:
mid(up_address,a(i),a(i+1)-a(i)-1)
‘a(chǎn)(i)是空格的位置
‘a(chǎn)(i+1)是下一個空格的位置
‘a(chǎn)(i+1)-a(i)-1是兩個空格直間的字符長度
現(xiàn)在的問題是,經(jīng)測試,mid的第三個參數(shù)那,無法使用減法,也就是說,我可以寫a(i+1)+,但不能寫a(i+1)-,想了好久,我一直不明白問題出在哪?應(yīng)該怎么來解決呢?
出現(xiàn)這個問題是因為上面的MID函數(shù)的第三個參數(shù)出現(xiàn)了負(fù)數(shù),下面是在網(wǎng)上找的測試的VBS代碼,原理一樣,如下的代碼:
VBScript code:
復(fù)制代碼 代碼如下:
dim a(),up_address
up_address = "aaa djaldk adflj adafadfasdfa afd ad"
MsgBox len(up_address) '36
redim a(len(up_address)) 'a(36)
a(0) = instr(up_address," ")
MsgBox a(0) 'a(0)=4
MsgBox a(0) & "<br />"
if a(0)<>0 then
for i=0 to len(up_address)-1
a(i+1) = instr(a(i)+1,up_address," ")
MsgBox a(i) &" "& (a(i+1)-1)‘這里的結(jié)果為34,-1,所以導(dǎo)致出錯
MsgBox mid(up_address,a(i),a(i+1)-1) & "<br />"
if a(i+1)=0 then
exit for
end if
MsgBox a(i+1) & "<br />"
next
end if
以上是“dim函數(shù)第三個參數(shù)如何設(shè)置截取字符的長度”這篇文章的所有內(nèi)容,感謝各位的閱讀!相信大家都有了一定的了解,希望分享的內(nèi)容對大家有所幫助,如果還想學(xué)習(xí)更多知識,歡迎關(guān)注億速云行業(yè)資訊頻道!
免責(zé)聲明:本站發(fā)布的內(nèi)容(圖片、視頻和文字)以原創(chuàng)、轉(zhuǎn)載和分享為主,文章觀點不代表本網(wǎng)站立場,如果涉及侵權(quán)請聯(lián)系站長郵箱:is@yisu.com進(jìn)行舉報,并提供相關(guān)證據(jù),一經(jīng)查實,將立刻刪除涉嫌侵權(quán)內(nèi)容。