This page has been translated automatically.
UnigineEditor
Interface Overview
Assets Workflow
Settings and Preferences
Adjusting Node Parameters
Setting Up Materials
Setting Up Properties
Landscape Tool
Using Editor Tools for Specific Tasks
FAQ
Programming
Fundamentals
Setting Up Development Environment
Usage Examples
C++
C#
UUSL (Unified UNIGINE Shader Language)
File Formats
Rebuilding the Engine and Tools
GUI
Double Precision Coordinates
API
Containers
Common Functionality
Controls-Related Classes
Engine-Related Classes
Filesystem Functionality
GUI-Related Classes
Math Functionality
Node-Related Classes
Networking Functionality
Pathfinding-Related Classes
Physics-Related Classes
Plugins-Related Classes
CIGI Client Plugin
Rendering-Related Classes
Warning! This version of documentation is OUTDATED, as it describes an older SDK version! Please switch to the documentation for the latest SDK version.
Warning! This version of documentation describes an old SDK version which is no longer supported! Please upgrade to the latest SDK version.

Foreachkey

The foreachkey construct provides another way to iterate over vectors and maps. It is used to execute some code for each index or key in a given container.

Syntax#

Source code (UnigineScript)
foreachkey(key_variable; map; loop_increment) {
	// some_code;
 }

Parts#

  • key_variable is the current key (or index). The internal container cursor is moved to point at the next key-value pair (or indexed item).
  • The type of key_variable doesn't matter.
  • loop_increment is executed at the end of each iteration. It is optional.

Examples#

  • Source code (UnigineScript)
    int map[] = ( "begin" : "flower", "middle" : "fruit", "end" : "tree" );
    foreachkey(int i; map) {
    	log.message("%s\t=>\t%s\n",i,map[i]);
    }
    The result is:
    Output
    begin   =>      flower
    end     =>      tree
    middle  =>      fruit
  • Source code (UnigineScript)
    int map[] = ( "begin" : "flower", "middle" : "fruit", "end" : "tree" );
    foreachkey(int i, j = 0; map; j++) {
    	log.message("%d: %s\t=>\t%s\n",j,i,map[i]);
    }
    The result is:
    Output
    0: begin   =>      flower
    1: end     =>      tree
    2: middle  =>      fruit
Notice
Before the execution keys are sorted in the ascending order.

Modifications of keys inside the foreachkey block do not affect the map, however, values can be modified directly.

Source code (UnigineScript)
int map[] = ( "begin" : "flower", "middle" : "fruit", "end" : "tree" );
foreachkey(int i; map) {
	i = "first";	// it doesn't affect the map
	map[i] = -9.6;	// it's ok, map is changed
}

Nesting foreachkey#

In case foreachkey structure is called within another foreachkey structure, for each block a copy of the map should be stored. (Such approach allows for higher performance.)

Source code (UnigineScript)
int map[] = ( "1" : "head", "2" : "foot" );

int copy[];
copy.copy(map);

foreachkey(int i; map) {
	foreachkey(int j; copy)	// foreachkey(int j; map) will generate an error
	{
		log.message("%s\t->\t%s\t%s\t->\t%s\n",i,map[i],j,map[j]);
	}
}
The output of the example is:
Output
1	->	head	1	->	head
1	->	head    2	->	foot
2	->	foot	1	->	head
2	->	foot	2	->	foot
Last update: 2018-12-27
Build: ()