See Also                  Applies To

Description

Retrieves the substring at the specified location within a String object.

Syntax

strVariable.substring(start, end)
"String Literal".substring(start, end)

The substring method syntax has these arguments:

Part	Description
start	The zero-based index indicating the beginning of the substring.
end	The zero-based index indicating the end of the substring.

Remarks

The substring method returns a String object containing the substring derived from the original object.

The substring method uses the lower of start and end as the beginning point of the substring. For example, strvar.substring(0, 3) and strvar.substring(3, 0) return the same substring.

The only exception to this is for negative parameters. If the first parameter is less than zero, it is treated as zero. If the second parameter is negative, it is set to the value of the first parameter.

The length of the substring is equal to the absolute value of the difference between start and end. For example, the length of the substring returned in strvar.substring(0, 3) and strvar.substring(3, 0) is three.

Finally, start and end can be strings. If so, these strings are coerced into integers if possible. If not, the value of the parameter is treated as zero.

The following example replaces a substring within a string. It will replace both individual characters and substrings. The function call at the end of the example changes the string "Brave New World" into "Brave New Web".

function replaceString(oldS,newS,fullS) {
// Replaces oldS with newS in the string fullS
   for (var i=0; i<fullS.length; i++) {
      if (fullS.substring(i,i+oldS.length) == oldS) {
         fullS = fullS.substring(0,i)+newS+fullS.substring(i+oldS.length,fullS.length)
      }
   }
   return fullS
}

replaceString("World","Web","Brave New World")

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