Bash += and -=: Difference between revisions
Jump to navigation
Jump to search
| (6 intermediate revisions by the same user not shown) | |||
| Line 4: | Line 4: | ||
=Internal= | =Internal= | ||
* [[Bash_Concepts#.2B.3D|bash Concepts]] | * [[Bash_Concepts#.2B.3D|bash Concepts]] | ||
* [[((...))|((...))]] | |||
=Overview= | =Overview= | ||
| Line 9: | Line 10: | ||
+= and -= are assignment operators that can be used to increment/decrement the value of the left operand with the value specified after the operator. The operators can be used on integral values as such: | += and -= are assignment operators that can be used to increment/decrement the value of the left operand with the value specified after the operator. The operators can be used on integral values as such: | ||
<syntaxhighlight lang='bash'> | <syntaxhighlight lang='bash'> | ||
i=0 | |||
((i+=1)) | |||
echo ${i} | |||
</syntaxhighlight> | </syntaxhighlight> | ||
displays: | |||
<syntaxhighlight lang='bash'> | <syntaxhighlight lang='bash'> | ||
1 | |||
</syntaxhighlight> | </syntaxhighlight> | ||
Also: | |||
<syntaxhighlight lang='bash'> | |||
i=0 | |||
((i-=1)) | |||
echo ${i} | |||
</syntaxhighlight> | |||
displays: | |||
<syntaxhighlight lang='bash'> | |||
-1 | |||
</syntaxhighlight> | |||
+= can be used on string values as such: | |||
<syntaxhighlight lang='bash'> | |||
s="something" | |||
s+=" else" | |||
echo ${s} | |||
</syntaxhighlight> | |||
displays: | |||
<syntaxhighlight lang='text'> | |||
something else | |||
</syntaxhighlight> | |||
-= does not work with strings. | |||
Latest revision as of 05:39, 8 May 2020
External
Internal
Overview
+= and -= are assignment operators that can be used to increment/decrement the value of the left operand with the value specified after the operator. The operators can be used on integral values as such:
i=0
((i+=1))
echo ${i}
displays:
1
Also:
i=0
((i-=1))
echo ${i}
displays:
-1
+= can be used on string values as such:
s="something"
s+=" else"
echo ${s}
displays:
something else
-= does not work with strings.