What does this html mean?

Just wondering what the 'event' keyword means in this instance? Is it a keyword and passing the actual event that will contain the keycode?

<asp:TextBox ID="tbSearch" runat="server" onkeyup="return dontSubmit(event);">

    <script type="text/javascript">

    function dontSubmit(event) {

        console.log('dont submit');
  开发者_JAVA百科      console.log(event.keyCode);

    }

</script>

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The event object is passed by the browser to event handlers when an event occurs in order so you can query different information about the event ( such as x/y position, key clicked, etc ).

Note: It can be named anything, so if you change function(event) to function(lol) and reference it with lol it would work the same way.

See https://developer.mozilla.org/en/DOM/Event for more info.

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in this case event is the keyup event

the keycode will map to which key was pressed

Here's a reference to see which key was pressed: http://www.cambiaresearch.com/c4/702b8cd1-e5b0-42e6-83ac-25f0306e3e25/Javascript-Char-Codes-Key-Codes.aspx

backspace = 8

tab = 9

enter = 13

shift = 16

ctrl = 17

alt = 18

pause/break = 19

caps lock = 20

escape = 27

page up = 33

page down = 34

end = 35

home = 36

left arrow = 37

up arrow = 38

right arrow = 39

down arrow = 40

insert = 45

delete = 46

0 = 48

1 = 49

2 = 50

3 = 51

4 = 52

5 = 53

6 = 54

7 = 55

8 = 56

9 = 57

a = 65

b = 66

c = 67

d = 68

e = 69

f = 70

g = 71

h = 72

i = 73

j = 74

k = 75

l = 76

m = 77

n = 78

o = 79

p = 80

q = 81

r = 82

s = 83

t = 84

u = 85

v = 86

w = 87

x = 88

y = 89

z = 90

left window key = 91

right window key = 92

select key = 93

numpad 0 = 96

numpad 1 = 97

numpad 2 = 98

numpad 3 = 99

numpad 4 = 100

numpad 5 = 101

numpad 6 = 102

numpad 7 = 103

numpad 8 = 104

numpad 9 = 105

multiply = 106

add = 107

subtract = 109

decimal point = 110

divide = 111

f1 = 112

f2 = 113

f3 = 114

f4 = 115

f5 = 116

f6 = 117

f7 = 118

f8 = 119

f9 = 120

f10 = 121

f11 = 122

f12 = 123

num lock = 144

scroll lock = 145

semi-colon = 186

equal sign = 187

comma = 188

dash = 189

period = 190

forward slash = 191

grave accent = 192

open bracket = 219

back slash = 220

close braket = 221

single quote = 222

single quote = 222

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The (event) is the onkeyup event.