✍ 📁 🙈 🙉 🙊 : string character position

String meta position 字串元位置,

<h3>indexOf() 字串尋找</h3>
<pre>stringObject.indexOf(searchvalue,fromIndex)
      字串尋找「由左至右尋找」將從頭到尾地檢索字串 stringObject，
      是否包含有 searchvalue。
      檢索開始的位置 fromIndex (沒有指定 fromIndex 時)。 
      如果找到一個 searchvalue ，轉回 searchvalue 所得位置。
  
    "0123456789ABCDEF".indexOf("456") = <script>document.write( "0123456789ABCDEF".indexOf("456")) </script>
    "0123456789ABCDEF".indexOf("456",2) = <script>document.write( "0123456789ABCDEF".indexOf("456",2)) </script>
    "0123456789ABCDEF".indexOf("456",8) = <script>document.write( "0123456789ABCDEF".indexOf("456",8)) </script>
    "0123456789ABCDEF".indexOf("AB") = <script>document.write( "0123456789ABCDEF".indexOf("AB")) </script>
    "0123456789ABCDEF".indexOf("939") = <script>document.write( "0123456789ABCDEF".indexOf("939")) </script>

</pre>

<h3>lastIndexOf() 字串反向尋找</h3>
  
<pre>stringObject.lastIndexOf(searchvalue,fromIndex)
      
      字串反向尋找「由右至左尋找」(反向)將從尾到頭地檢索字串，
      stringObject 看它是否含有子串 searchvalue。
      開始檢索的位置(左)在字串的 fromIndex 處或沒有指定則為字串的結尾。
      
   
    var TxT = "0123456789ABCDEF"
    TxT.lastIndexOf("456",15) = <script>document.write( TxT.lastIndexOf("456",15)) </script>
    TxT.lastIndexOf("456",2)  = <script>document.write( TxT.lastIndexOf("456",2)) </script>
    TxT.lastIndexOf("456",8)  = <script>document.write( TxT.lastIndexOf("456",8)) </script>
    TxT.lastIndexOf("AB")     = <script>document.write( TxT.lastIndexOf("AB")) </script>
    TxT.lastIndexOf("939")    = <script>document.write( TxT.lastIndexOf("939")) </script>

</pre>

<h3>startsWith() 判斷字符串是否以指定的子字符串開始</h3>
  
<pre>   string.startsWith(searchvalue, start)
      方法用於 檢測 searchvalue 是否是指定的子串開始。
      searchvalue : 要查找的字符串
      start : 查找的開始位置，默認為 0。

"hi Hello World".startsWith("hi")      =   <script>document.write( "hi Hello World".startsWith("hi") ) </script>
    "hi Hello World".startsWith("Hello")   =   <script>document.write( "hi Hello World".startsWith("Hello") ) </script>
    "hi Hello World".startsWith("World")   =   <script>document.write( "hi Hello World".startsWith("World") ) </script>
    "hi Hello World".startsWith("World",9) =   <script>document.write( "hi Hello World".startsWith("World",9) ) </script>
</pre>

<h3>endsWith() 判斷字符串是否以指定的子字符串結尾</h3>

<pre>   stringObject.endsWith(searchvalue, start)
        方法用於 檢測 searchvalue 是否是指定的子串結尾。
        searchvalue : 要查找的字符串
        start : 查找的開始位置，默認為 0。
      
    "hi Hello World".endsWith("hi")      =   <script>document.write( "hi Hello World".endsWith("hi") ) </script>
    "hi Hello World".endsWith("Hello")   =   <script>document.write( "hi Hello World".endsWith("Hello") ) </script>
    "hi Hello World".endsWith("World")   =   <script>document.write( "hi Hello World".endsWith("World") ) </script>
    "hi Hello World".endsWith("Hello",11) =   <script>document.write( "hi Hello World".endsWith("Hello",11) ) </script>

</pre>

<h3>test() 方法用於檢測一個字符串是否匹配某個模式</h3>

<pre>   RegExpObject.test(string)
     RegExpObject : 字符串是否全在。
     string : 要檢測的字符串。
          
    /hi/.test('hi Hello World')    =   <script>document.write( /hi/.test('hi Hello World') ) </script>
    /Hello/.test('hi Hello World') =   <script>document.write( /Hello/.test('hi Hello World') ) </script>
    /World/.test('hi Hello World') =   <script>document.write( /World/.test('hi Hello World') ) </script>
    /love/.test('hi Hello World')  =   <script>document.write( /love/.test('hi Hello World') ) </script>
    /r/.test('hi Hello World')     =   <script>document.write( /r/.test('hi Hello World') ) </script>
    /R/.test('hi Hello World')     =   <script>document.write( /R/.test('hi Hello World') ) </script>

</pre>

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