#!/bin/sh

num1=10
num2=20
# if then fi
if [ ${num1} -gt ${num2} ]
then
echo "大于"
fi

# if then ... else ... fi
if [ ${num1} -gt ${num2} ]
then
echo "大于"
else
echo "小于或等于"
fi

# if then ... elif then ... else ... fi 
if [ ${num1} -gt ${num2} ]
then
echo "大于"
elif [ ${num1} == ${num2} ]
then
echo "等于"
else
echo "小于"
fi


# for in 循环,语法:for 变量名 in 元素1 元素2 ~ 元素n do ... done
for name in "iOSZhang" "testLiu" "JavaYang"
do
echo ${name}
done

# 或
for name in iOSZhang\`s an iOS developer
do
echo ${name}
done

# 或从变量列表里读取
names=("iOSZhang" "testLiu" "JavaYang")
for name in ${names}
do
echo ${name}
done

# 或目录文件读取
filePath="/Users/zhangshaoyu/Desktop/MinePods/OSChina/LearnShell/code/*"
for file in ${filePath}
do
echo $file
done

# for嵌套循环,语法:for (i = 0; i < n; i++) do ... done
names=("iOSZhang" "testLiu" "JavaYang")
for (( i = 0; i < 3; i++ ))
do
value=${names[i]}
	echo ${value}
done


# while循环
i=0
while (( i < ${#names[@]} ))
do
value=${names[i]}
	echo ${value}
	let 'i++'
done


# case语句
age=1
case ${age} in 
1)
		echo "== 1"
	;;
	2)
		echo "== 2"
	;;
	3)
		echo "== 3"
	;;
esac

# break退出循环
for (( i = 0; i < 10; i++ ))
do
	if [[ $i -eq 5 ]]
	then
break
fi
echo $i
done

# contiune退出当前循环
for (( i = 0; i < 10; i++ ))
do
	if [ $i -eq 5 ]
	then
		continue
	fi
echo $i
done