Table of Contents

• 1. string
  • 1.1. Syntax
  • 1.2. Stack Effects
  • 1.3. Description
  • 1.4. PostScript Level
  • 1.5. Examples
  • 1.6. Common Use Cases
    • 1.6.1. String Buffer Creation
    • 1.6.2. File I/O Buffers
    • 1.6.3. Dynamic String Construction
  • 1.7. Common Pitfalls
  • 1.8. Error Conditions
  • 1.9. Implementation Notes
  • 1.10. Performance Considerations
  • 1.11. See Also

1. string

Creates a new string of specified length with all elements initialized to zero.

1.1. Syntax

int string → string

1.2. Stack Effects

Table 1. Before

Level	Object
0	int (non-negative integer)

Table 2. After

Level	Object
0	string (new string of length int)

1.3. Description

string creates a string object of length int, with each element initialized to the integer 0 (null character). The string is allocated in local or global VM according to the current VM allocation mode.

The int operand must be: * A non-negative integer * Not greater than the maximum allowable string length (implementation-dependent)

1.4. PostScript Level

Level 1 and later

1.5. Examples

Creating a string

10 string  % Creates string of 10 null characters

Building a string

3 string
dup 0 65 put  % 'A'
dup 1 66 put  % 'B'
dup 2 67 put  % 'C'
% Result: (ABC)

Buffer allocation

/buffer 100 string def  % Allocate 100-char buffer

1.6. Common Use Cases

1.6.1. String Buffer Creation

% Create buffer for cvs
20 string /buf exch def
123 buf cvs  % Convert number to string

1.6.2. File I/O Buffers

/readbuf 256 string def
file readbuf readline

1.6.3. Dynamic String Construction

% Calculate required size
text1 length text2 length add string
% Build composite string
dup 0 text1 putinterval
dup text1 length text2 putinterval

1.7. Common Pitfalls

All Elements Initialized to Zero - The string contains null characters (ASCII 0), not spaces or empty.

5 string  % Not empty, contains 5 null chars

String Literals vs. string Operator - For known text, use string literals (…​). Use string for dynamic buffers.

(Hello)     % Literal string (preferred for constants)
5 string    % Dynamic allocation (for buffers)

Calculate Size Dynamically - Use length to determine buffer sizes.

original length string  % Same size as original

1.8. Error Conditions

Error	Condition
[limitcheck]	int exceeds maximum string length
[rangecheck]	int is negative
[stackunderflow]	No operand on stack
[typecheck]	Operand is not an integer
[VMerror]	Insufficient VM to allocate string

1.9. Implementation Notes

• Most implementations support strings up to 65,535 characters

• Strings are mutable (can be modified after creation)

• String elements are integers 0-255 (byte values)

• Strings allocated in current VM (local or global)

1.10. Performance Considerations

• Creating strings is very fast

• Pre-allocate buffers for repeated use

• Strings are more memory-efficient than arrays for byte data

• Consider reusing buffers instead of creating many temporary strings

1.11. See Also

• length - Get string length

• get - Get character code

• put - Put character code

• getinterval - Get substring

• putinterval - Put substring

• cvs - Convert object to string