# 配列の要素�A
names = ["Perl", "Python", "Ruby", "Scheme"]
p names[ 0 ]
p names[ 1 ]
p names[ 2 ]
p names[ 3 ]

# 配列の要素�B
names = ["Perl", "Python", "Ruby", "Scheme"]
names.length

# 配列の要素への代入�A
names = ["Perl", "Python", "Ruby", "Scheme"]
names[ 0 ] = "C"
names[ 3 ] = "Java"
p names

# Ruby の配列は柔軟
abc = ["a","b","c"]
abc[10] = "k"
p abc

# 各要素に代入する（失敗編）
primes[0]=2

# 配列だということを教える�@
abc = Array.new( 5 )
abc[3]=333
p abc

# 配列だということを教える�B
x=[]
x[ 0 ] = 3
x[ 1 ] = 5
p x

# 要素番号を用いて一つずつ取り出す
names=["Perl", "Python", "Ruby", "Scheme"]
4.times { | i | print( "#{i} 番目は #{ names[i] }\n" ) }

# 要素番号を用いて一つずつ取り出す（続）
names=["Perl", "Python", "Ruby", "Scheme"]
names.length.times { | i | print( "#{i} 番目は #{ names[i] }\n" ) }

# 要素を直接一つずつ取り出す
["Perl", "Python", "Ruby", "Scheme"].each { | lang |
   print( "I like ", lang, "\n" )
}

# 要素を直接一つずつ取り出す（続）
names=["Perl", "Python", "Ruby", "Scheme"]
names.each { | lang | print( "I like #{lang}\n" ) }

# 試してみよう 4
names=["Perl", "Python", "Ruby", "Scheme"]
names[0] = "Ada"
names.length.times { | i | 
	print( "#{i} 番目は #{ names[i] }\n" )
}

# 試してみよう 6
abc = ["a","b","c"]
abc[1] = 111
p abc
=> ["a", 111, "c"]
abc[3] = 3.33
p abc
p abc[4] = [4,5,6]
p abc

# 配列の要素の参照例�@
a=[4,2,1,6,7]
sum = 0
a.length.times{ |i|
	sum += a[ i ]
}
print( " sum = " , sum )

a=[4,2,1,6,7]
sum = 0
a.each{ |i|
	sum += i
}
print( " sum = " , sum , "\n" )

# 配列の要素の参照例�A
a=[4,2,1,6,7]
i = 0
sum = 0
while i < a.length do
	sum += a[ i ]
	i += 1
end
print( " sum = " , sum )

a=[4,2,1,6,7]
i = 0
sum = 0
loop{
	sum += a[ i ]
	i += 1
	break if i == a.length
}
print( " sum = " , sum )

# 配列の要素の参照例�B
a=[4,2,1,6,7]
a.length.times { |i|
    if i % 2 != 0 then
	print( a[ i ] , "\n" )
    end
}

a=[4,2,1,6,7]
a.each { |i|
     if i % 2 != 0 then
	print( i , "\n" )
     end
}

# 配列の要素の参照例�C
x=[]
10.times{ |i|
	x[ i ] = rand( 100 )
}
sum = 0
x.length.times{ |i|
	sum += x[ i ]
}
p x
print( " sum = " , sum )

# 配列の要素の参照例�D
a=[4,2,1,6,7]
a.length.times { |i|
	print( a[ a.length-1-i ] , "\n" )
}

a=[4,2,1,6,7]
(a.length-1).step(0,-1){ |i|
	print( a[ i ] , "\n" )
}

# 配列の要素の参照例�E
a=[4,2,1,6,7]
x=[]
a.length.times { |i|
     x[ i ] =  a[ i ]
}
p x

a=[4,2,1,6,7]
x=[]
a.length.times { |i|
     x[ i ] =  a[ i ]*a[ i ]
}
p x

# 配列の要素の参照例�E'
a=[4,2,1,6,7]
x=Array.new(a.length)
a.length.times { |i|
     x[ i ] =  a[ i ]
}
p x

a=[4,2,1,6,7]
x=Array.new(a.length)
a.length.times { |i|
     x[ i ] =  a[ i ]*a[ i ]
}
p x

# 配列の要素の参照例�F
a=[4,2,1,6,7]
a[ a.length ] = 8
p a

# 配列の要素の参照例�G
a=[4,2,1,6,7]
n=a.length
n.times{ |i|
　　a[ n-i ] = a[ n-i-1 ]
}
a[ 0 ] = 5
p a

# 配列の要素の参照例�H
e=[]
n = 100
fact = 1.0
e[ 0 ] = 1.0
(1..n).each{ |x|
	fact = fact * x.to_f
	e[ x ] = e[ x-1 ] + 1.0 / fact	
}
e.length.times{ |i|
	printf( "%3d: %64.60f\n" , i , e[ i ] )
} 

# 配列の要素の参照例�I
a=[]
n=10
n.times{ |i|
	a[ i ] = rand( 10 )
}
a.length.times { |i|
	print( a[ i ] , " " , "*" * a[ i ] , "\n" )
}

# コマンドライン引数：プログラム(sample0302.rb)
print( ARGV[0] + " + " + ARGV[1]+ " = " )
print( ARGV[0].to_i + ARGV[1].to_i )

print( "#{ARGV[0]} + #{ARGV[1]} = " )
print( ARGV[0].to_i + ARGV[1].to_i )

# 浮動小数点数にすると(sample0303.rb)
print( ARGV[0] + " + " + ARGV[1]+ " = " )
print( ARGV[0].to_f + ARGV[1].to_f )

# 3個にすると(sample0304.rb)
print( ARGV[0] + " + " + ARGV[1] + " + " + ARGV[2] + " = " )
print( ARGV[0].to_f + ARGV[1].to_f + ARGV[2].to_f )