c - Unicode escape sequences vs hexadecimal values -


to encode unicode/utf-8 characters in program, i've been using \uxxxx escape sequences, such as:

wchar_t superscript_4 = l'\u2074';  // u+2074 superscript 4 '⁴' wchar_t subscript_4   = l'\u2084';  // u+2084 subscript 4 '₄'

however, using hexadecimal should work fine, since unicode encoded in hexadecimal.

wchar_t superscript_4 = 0x2074; wchar_t subscript_4   = 0x2084;

will second example encode character properly? run wide-char issues, segmentation faults, or incorrectly stored character values? if so, why? if not, why?

you could initialize them hex constants, initialize normal chars numeric constants, e.g. char c = 67;. works same way; assigns whatever char or wchar_t has value of int. in example give, , assuming unicode execution environment (not quite guaranteed highly probable) it’s subscript or superscript 4; in example it’s capital c.

in particular, regular chars, technically character constants 'c' have type int, , assigning int values chars. wchar_ts, constants have wchar_t type, , integral value same value you’d calling mbtowc. assuming you’re working in unicode environment, hex constants equivalent unicode escapes.

usually don’t want this, though; using character literals makes clearer intention is. true if use non-ascii characters in source code, in case can make code be

wchar_t superscript_4 = l'⁴' wchar_t subscript_4   = l'₄'

also note many purposes it’s better use char16_t or char32_t, because wchar_t can have different widths on different platforms; might cleaner use utf-8 until have specific need switch else.


Comments

Post a Comment

Popular posts from this blog

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m
Read more

javascript - Z-index in d3.js -

i have map , when hover effect on region of map below yellow line , circle, last ones disappear. how can solve problem? http://jsfiddle.net/ot21n9qx/ var arc = g.append("path") .style("fill", "none") .style("stroke", "yellow") .style("stroke-width", 2) .attr("d", "m" + pathorigin[0] + "," + pathorigin[1] + " q" + svgpoint[0] + "," + pathorigin[1] + " " + svgpoint[0] + "," + svgpoint[1]); var circlesize = d3.scale.linear() .domain([0, 0.5, 1]) .range([4, 10, 4]); svg not have z order draws objects in order created. need create path , circle after create highlight regions. here forked fiddle: http://jsfiddle.net/o00fzgaf/1/
Read more