This is a nice easy way to add values to strings and just create strings easily.<\/p>\n\n\n\n
#include <sstream>\n\t\n\tstringstream ss1;\n\tint myInt = 54;\n\tdouble myDouble = 1.234;\n\tss1 << \"The int is \" << myInt;\n\tss1 << \", and the double is \" << myDouble;\t\t\/\/You can add to a stringstream like this\n\n\t\/\/If you want to then pass the stringstream to a string:\n\tstring s1 = ss1.str();<\/code><\/pre>\n\n\n\nGet variable from string<\/h5>\n\n\n\n#include <sstream>\n\n\tstringstream ss1;\n\tint my_value;\n\t\/\/float my_value;\n\t\/\/double my_value;\n\tss1 << \"1.234\";\n\tss1 >> my_value;\t\t\/\/Will convert to int, float, double<\/code><\/pre>\n\n\n\nConverting double to string with a fixed number of decimal places<\/h4>\n\n\n\n\/\/**********************************************************************************\n\/\/********** CONVERT DOUBLE TO STRING WITH FIXED NUMBER OF DECIMAL DIGITS **********\n\/\/**********************************************************************************\n\/\/#include <string.h>\n\/\/#include <iostream>\n\/\/#include <iomanip>\nvoid convert_double_to_string_fixed_precision (double value, string *output_string, int number_of_digits)\n{\n\tstringstream stream;\n\tstream << fixed << setprecision(number_of_digits) << value;\t\/\/\"fixed\" as otherwise scientific notation can get used or value can be rounded to less digits (yes it does happen!)\n\t*output_string = stream.str();\n}<\/code><\/pre>\n\n\n\nModifiers<\/h4>\n\n\n\n
“hex”<\/p>\n\n\n\n
Make values hexadecimal. Persistent. Reset back to normal by using “dec”.<\/p>\n\n\n\n
uppercase<\/p>\n\n\n\n
Make values beign turned into hex for instance uppercase. Does not affect strings. Persistent. Reset with “nouppercase”.<\/p>\n\n\n\n
setfill(‘0’)<\/p>\n\n\n\n
Set the fill character for leading and trailing spaces. Persistent. Reset to default with “setfill(‘ ‘)”<\/p>\n\n\n\n
setw(2)<\/p>\n\n\n\n
Set the width of a value by inserting fill characters if necessary. NOT presistent, must be used prior to each value.<\/p>\n\n\n\n
Adding Leading Zero’s, Spaces, etc<\/h4>\n\n\n\n\/\/#include <iomanip>\n\tcout << setfill('0') << setw(4) << 15;\n\n\t\/\/Reset the setfill persistent modifier back to normal if carrying on adding things to the stream (setw is not persistent)\n\tcout << setfill(' ');<\/code><\/pre>\n\n\n\nWill output: 0015<\/p>\n\n\n\n
BYTE Values<\/h4>\n\n\n\n
If you output variables and they are BYTE then you may need to use (int) to convert them to an int to display properly.<\/p>\n\n\n\n
\tss1 << hex << uppercase << setfill('0') << setw(2) << (int)message_to_send_data[count];<\/code><\/pre>\n\n\n\nExamples<\/h4>\n\n\n\nDateTime Values<\/h5>\n\n\n\n\t\/\/Create as yyyymmddhh\n\tstringstream ss1;\n\tss1 << (tmFromDate.tm_year + 1900);\t\t\t\t\t\t\t\/\/2000 - 2099\n\tss1 << setfill('0') << setw(2) << (tmFromDate.tm_mon + 1);\t\/\/1-12\n\tss1 << setfill('0') << setw(2) << tmFromDate.tm_mday;\t\t\t\/\/1-31\n\tss1 << setfill('0') << setw(2) << tmFromDate.tm_hour;\t\t\t\/\/0-23\n\n\t\/\/Create in UTC format\n\tstringstream ss1;\n\tss1 << (tmFromDate.tm_year + 1900) << \"-\";\t\t\t\t\t\t\t\/\/2000 - 2099\n\tss1 << setfill('0') << setw(2) << (tmFromDate.tm_mon + 1) << \"-\";\t\t\/\/1-12\n\tss1 << setfill('0') << setw(2) << tmFromDate.tm_mday << \" \";\t\t\t\/\/1-31\n\tss1 << setfill('0') << setw(2) << tmFromDate.tm_hour << \":\";\n\tss1 << setfill('0') << setw(2) << tmFromDate.tm_min << \":\";\n\tss1 << setfill('0') << setw(2) << tmFromDate.tm_sec;<\/code><\/pre>\n\n\n\nHex Values<\/h5>\n\n\n\n\tcout << hex << uppercase << setfill('0') << setw(2) << 0 << \":\" << setw(2) << 2 << \":\" << setw(2) << 15 << \":\" << setw(2) << 16 << \":\" << setw(2) << 254 << \":\" << setw(2) << 255 << \",\";\t\t\/\/setw() is not persistent so has to be used before each value\n\tcout << 15 << \",\";\n\tcout << \"heLLo1\" << \",\";\n\n\t\/\/Reset the hex, setfill and uppercase persistent modifiers back to normal if carrying on adding things to the stream (setw is not persistent)\n\tcout << dec << setfill(' ') << nouppercase;\t\t\n\tcout << 15 << \",\";\n\tcout << \"heLLo2\" << \",\";\n\tcout << endl;<\/code><\/pre>\n\n\n\nOutputs this:<\/p>\n\n\n\n
00:02:0F:10:FE:FF,F,heLLo1,15,heLLo2,<\/code><\/pre>\n\n\n\nNOTE:<\/p>\n\n\n\n
If you output variables\u00a0and they are BYTE then you will need to use (int) to convert them to an int to work properly<\/em><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"Using the stringstream class Add variable to string This is a nice easy way to add values to strings and just create strings easily. Get variable from string Converting double to string with a fixed number of decimal places Modifiers “hex” Make values hexadecimal. Persistent. Reset back to normal by using “dec”. uppercase Make values beign […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[97,141],"tags":[],"class_list":["post-2017","post","type-post","status-publish","format-standard","hentry","category-string-class","category-stringstream"],"_links":{"self":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts\/2017","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/comments?post=2017"}],"version-history":[{"count":19,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts\/2017\/revisions"}],"predecessor-version":[{"id":3404,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/posts\/2017\/revisions\/3404"}],"wp:attachment":[{"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/media?parent=2017"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/categories?post=2017"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/raspberry-projects.com\/pi\/wp-json\/wp\/v2\/tags?post=2017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}