Create a string array that contains addresses. Each address ends with a US ZIP code.

str = ["73 Beacon St., Boston, MA, 02116";
       "1640 Riverside Dr., Hill Valley, CA, 92530";
       "138 Main St., Cambridge, MA, 02138"]

str = 3x1 string
    "73 Beacon St., Boston, MA, 02116"
    "1640 Riverside Dr., Hill Valley, CA, 92530"
    "138 Main St., Cambridge, MA, 02138"

Create a pattern that matches any sequence of digits.

pat = digitsPattern

pat = pattern
  Matching:

    digitsPattern

Use it to extract all sequences of digits from the addresses.

newStr = extract(str,pat)

newStr = 3x2 string
    "73"      "02116"
    "1640"    "92530"
    "138"     "02138"

The digitsPattern pattern matches street numbers, apartment numbers, and ZIP codes. To match only ZIP codes, create a pattern that matches a sequence of digits at the end of an address.

pat = digitsPattern + textBoundary

pat = pattern
  Matching:

    digitsPattern + textBoundary

Extract the ZIP codes.

newStr = extract(str,pat)

newStr = 3x1 string
    "02116"
    "92530"
    "02138"

For a list of functions that create pattern objects, see pattern.

Create a string.

str = "All's well that ends well"

str = 
"All's well that ends well"

Extract the first character in the string.

extract(str,1)

ans = 
"A"

Extract the last character.

extract(str,strlength(str))

ans = 
"l"