mirror of
https://github.com/beyondx/Notes.git
synced 2026-02-03 10:23:27 +08:00
38 lines
803 B
Plaintext
38 lines
803 B
Plaintext
Content-Type: text/x-zim-wiki
|
|
Wiki-Format: zim 0.4
|
|
Creation-Date: 2011-11-28T10:07:29+08:00
|
|
|
|
====== expr ======
|
|
Created Monday 28 November 2011
|
|
|
|
对表达式求值：
|
|
|
|
[geekard@geekard ~]$ expr 2 \+ 3 #算术运算符只对整数有效
|
|
5
|
|
[geekard@geekard ~]$ expr 2 \* 3.2
|
|
expr: non-integer argument
|
|
[geekard@geekard ~]$ expr 2 \* 3
|
|
6
|
|
[geekard@geekard ~]$ expr 2 \- 3
|
|
-1
|
|
[geekard@geekard ~]$ expr 2 \/ 3
|
|
0
|
|
[geekard@geekard ~]$ expr 2 \% 3
|
|
2
|
|
[geekard@geekard ~]$ expr 2 \& 3
|
|
2
|
|
[geekard@geekard ~]$ expr 2 \<= 3 #关系运算符对数字字符和字符串都是有效的
|
|
1
|
|
[geekard@geekard ~]$ expr 2 \<= 1
|
|
0
|
|
[geekard@geekard ~]$ expr 2 \= 2
|
|
1
|
|
[geekard@geekard ~]$ expr 2 \= 3
|
|
0
|
|
[geekard@geekard ~]$ expr aff \= fdf
|
|
0
|
|
[geekard@geekard ~]$ expr aff \= aff
|
|
1
|
|
[geekard@geekard ~]$ expr aff \>= aee
|
|
1
|