mirror of
https://github.com/tcltk/tcl.git
synced 2026-05-29 00:27:49 +08:00
71 lines
1.9 KiB
Plaintext
71 lines
1.9 KiB
Plaintext
'\"
|
|
'\" Copyright (c) 1993 The Regents of the University of California.
|
|
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
|
|
'\"
|
|
'\" See the file "license.terms" for information on usage and redistribution
|
|
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
|
'\"
|
|
.TH incr n "" Tcl "Tcl Built-In Commands"
|
|
.so man.macros
|
|
.BS
|
|
'\" Note: do not modify the .SH NAME line immediately below!
|
|
.SH NAME
|
|
incr \- Increment the value of a variable
|
|
.SH SYNOPSIS
|
|
\fBincr \fIvarName \fR?\fIincrement\fR?
|
|
.BE
|
|
.SH DESCRIPTION
|
|
.PP
|
|
Increments the value stored in the variable whose name is \fIvarName\fR.
|
|
The value of the variable must be an integer.
|
|
If \fIincrement\fR is supplied then its value (which must be an
|
|
integer) is added to the value of variable \fIvarName\fR; otherwise
|
|
1 is added to \fIvarName\fR.
|
|
The new value is stored as a decimal string in variable \fIvarName\fR
|
|
and also returned as result.
|
|
.PP
|
|
Starting with the Tcl 8.5 release, the variable \fIvarName\fR passed
|
|
to \fBincr\fR may be unset, and in that case, it will be set to
|
|
the value \fIincrement\fR or to the default increment value of \fB1\fR.
|
|
.VS TIP508
|
|
If \fIvarName\fR indicate an element that does not exist of an array that has
|
|
a default value set, the sum of the default value and the \fIincrement\fR (or
|
|
1) will be stored in the array element.
|
|
.VE TIP508
|
|
.SH EXAMPLES
|
|
.PP
|
|
Add one to the contents of the variable \fIx\fR:
|
|
.PP
|
|
.CS
|
|
\fBincr\fR x
|
|
.CE
|
|
.PP
|
|
Add 42 to the contents of the variable \fIx\fR:
|
|
.PP
|
|
.CS
|
|
\fBincr\fR x 42
|
|
.CE
|
|
.PP
|
|
Add the contents of the variable \fIy\fR to the contents of the
|
|
variable \fIx\fR:
|
|
.PP
|
|
.CS
|
|
\fBincr\fR x $y
|
|
.CE
|
|
.PP
|
|
Add nothing at all to the variable \fIx\fR (often useful for checking
|
|
whether an argument to a procedure is actually integral and generating
|
|
an error if it is not):
|
|
.PP
|
|
.CS
|
|
\fBincr\fR x 0
|
|
.CE
|
|
.SH "SEE ALSO"
|
|
expr(n), set(n)
|
|
.SH KEYWORDS
|
|
add, increment, variable, value
|
|
.\" Local variables:
|
|
.\" mode: nroff
|
|
.\" fill-column: 78
|
|
.\" End:
|