Question

目前正在处理Ruby中的HackerRank问题。当我尝试编译

时

in `+': String can't be coerced into Fixnum (TypeError)

在以下一行

print  d + double

我不明白，因为这两个变量都不是字符串。

i = 4
d = 4.0
s = 'HackerRank'

# Declare second integer, double, and String variables.
intOne = 12
double = 4.0
string = "is the best place to learn and practice coding!, we get HackerRank is the best place to learn and practice coding!"

# Read and save an integer, double, and String to your variables.
intOne = gets.chomp
double = gets.chomp
string = gets.chomp
# Print the sum of both integer variables on a new line.
print i + intOne
# Print the sum of the double variables on a new line.
print d + double
# Concatenate and print the String variables on a new line
print s + string
# The 's' variable above should be printed first.

Answer 1

如果要将其添加到字符串

，则必须在整数/浮点数上调用方法.to_s

例如：

i = 3
b = ' bah '

c = i.to_s + b 
# => '3 bah'

或者如果您有这样的字符串：＆＃39; 3＆＃39;，并且您希望从此字符串整数获取，如果您想要迭代，则必须调用to_i方法，to_f它是您想要的浮

例如：

i = '3'
g = i.to_f
# => 3

Answer 2

您已定义double两次：

double = 4.0  #Float type
double = gets.chomp #String type

因此，double类型的String已覆盖Float类型。

您已定义：

d = 4.0 #Float type

所以当你这样做时：

print d + double  #actually you are doing here (Float + String)

Answer 3

由于double

，

gets.chomp是一个字符串

在`+'中：字符串无法强制转换为Fixnum（TypeError）

3 个答案: