string extract

string extraction 字串提取

<script>var TxT = "0123456789ABCDEF"</script> <h3>substr() 提取字串中的幾個字</h3> <pre>stringObject.substr(start, length) start : 是一個數字,位置從 0 開始, 如果 start 是一個負數，從尾倒數。 length : 總共要取出幾個字元， 如果 length 大個字串 取到字串結尾。 var TxT = "0123456789ABCDEF" TxT.length = 16 TxT.substr( 0) = <script>document.write(TxT.substr(0)) </script> TxT.substr( 4) = <script>document.write(TxT.substr(4)) </script> TxT.substr(-4) = <script>document.write(TxT.substr(-4)) </script> TxT.substr(4,3) = <script>document.write(TxT.substr(4,3)) </script> TxT.substr(4,30) = <script>document.write(TxT.substr(4,30)) </script> TxT.substr(-4,4) = <script>document.write(TxT.substr(-4,4)) </script> </pre> <style> h3 {text-align: center; font-size: 30px; font-weight: bold; text-shadow: 10px 6px 10px grey; color: blue; } pre {font-size: 20px;} ol {background-color:tan ;} li {background-color:ivory ;padding-left:10px;text-align: left;} li {word-break: break-word } r { color:red} </style>

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<script>var TxT = "0123456789ABCDEF"</script> <h3>substring() 提取字串中兩個指定索引號之間的字元</h3> <pre>stringObject.substring(start, index) start : 必需。一個非負的整數，開始位置。 index : 可選。一個非負的整數，結束位置，如果省略該參數， 那麼返回的子串會一直到字符串對象的結尾。 "0123456789ABCDEF".length = 16 "0123456789ABCDEF".substring( 0) = <script>document.write("0123456789ABCDEF".substring(0)) </script> "0123456789ABCDEF".substring( 4) = <script>document.write("0123456789ABCDEF".substring(4)) </script> "0123456789ABCDEF".substring(-4) = <script>document.write("0123456789ABCDEF".substring(-4)) </script> "0123456789ABCDEF".substring(4,6) = <script>document.write("0123456789ABCDEF".substring(4,6)) </script> "0123456789ABCDEF".substring(4,30) = <script>document.write("0123456789ABCDEF".substring(4,30)) </script> "0123456789ABCDEF".substring(-4,4) = <script>document.write("0123456789ABCDEF".substring(-4,4)) </script> </pre> <style> h3 {text-align: center; font-size: 30px; font-weight: bold; text-shadow: 10px 6px 10px grey; color: blue; } pre {font-size: 20px;} ol {background-color:tan ;} li {background-color:ivory ;padding-left:10px;text-align: left;} li {word-break: break-word } r { color:red} </style>

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#html #網頁格式 #style #div #string extraction 字串提取 #substr() 提取字串中的幾個字 #substring() 提取字串中兩個指定索引號之間的字元 #slice() 取得部份字串 #script substr() #script substring() #script slice()