The simplest JavaScript validates integer decimal real and valid decimal regular expressions
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<title> Verify that the number is the simplest of all regular expressions </title>
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<h3> After typing, press enter to verify! (think it's the easiest!) </h3>
Positive integer : <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^/d+$/.test(this.value));" />
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Negative integer : <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-/d+$/.test(this.value));" />
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The integer : <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?/d+$/.test(this.value));" />
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Is the decimal : <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^/d+/./d+$/.test(this.value));" />
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Negative decimal : <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-/d+/./d+$/.test(this.value));" />
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The decimal : <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?/d+/./d+$/.test(this.value));" />
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The set of real Numbers : <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?/d+(/./d+)?$/.test(this.value));" />
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keep 1 Decimal places :<input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?/d+(/./d{1,1})?$/.test(this.value));" />
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keep 2 Decimal places :<input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?/d+(/./d{1,2})?$/.test(this.value));" />
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keep 3 Decimal places :<input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?/d+(/./d{1,3})?$/.test(this.value));" />
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