Javascript -- String

String Length:

<script>
    var txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    var sln = txt.length;
</script>

Sepcial Characters:

<script>
    var x = "It\'s alright";
    var y = "We are the so-called \"Vikings\" from the north ";
</script>

Finding a String in a String

　　*indexOf() returns the index of the first occurence of a specified text in a string

<script>
   var str="Hello everyone, I am from Dongguan!";
   var pos = str.indexOf("I");
</script>

 

　　*lastIndexOf() returns the index of the last occurence of a specified text

<script>
    var str ="I am from Dongguan and Dongguan is famous for Manufacturing";
</script>

Searching for a String in a String

　　*search() searches a string for a specified value and returns the positions of the match:

<script>
    var str = "Please locate where 'locate' occurs!";
    var pos = str.search("locate");
</script>

Extracting String Parts:

　　*slice(start, end): extracts a part of a string and returns the extracted part in a new string.

　　*substring(start,end):

　　*substr(start,length):

Extract String Characters:

　　*charAt(position): returns the character at a specified index

　　*charCodeAt(position):returns the unicode of the character at a specified index.

Replacing String Content:

　　*replace(): replaces a specified value with another value in a string.

<script>
  var str = "Please visit my city Dongguan";
  var newStr = str.replace("Dongguan","Hobart");
</script>

Converting to Upper and Lower Case

　　*str.toUpperCase();

　　*str.toLowerCase();

Converting a String to an Array:

　　*str.split();

<script>
  var txt = "a,b,c,d,e";
  var txtArray = txt.split(",");  // split on commas
</script>

 

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