Ruby: String Operations
String Length
Length of the string is .length
method.
# ruby xx="this" p xx.length == 4
Substring
Substring extraction is done by appending a bracket
string[index, count]
to get just 1 character, use:
string[index]
# ruby xx = "01234567" p xx[3] == "3" p xx[0,2] == "01" # negative index counts from end. -1 is last char. p xx[-2,2] == "67"
String Join
Strings can be joined by a plus sign +
.
# ruby p "aa" + "bb" == "aabb"
String Repetition
String can be repeated using *
.
# ruby print "this" * 2 # thisthis
Replacing substring
# ruby # replacing string xx = "0123456789" xx[1]= "a" p xx == "0a23456789" # start at index 1, replace 8 chars xx[1,8]= "what" p xx == "0what9"
Find substring
# ruby # get the start index of a substring p "in love?".index("love") == 3 p "in love?".index("456") == nil # not found
Split a string into a array
# ruby p "once upon a time".split(" ") == ["once", "upon", "a", "time"]