mirror of
https://github.com/chubin/cheat.sheets
synced 2024-11-17 09:25:32 +00:00
59 lines
1.5 KiB
Plaintext
59 lines
1.5 KiB
Plaintext
// Generate a random string
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Math.random().toString(36).substr(2);
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// Clone an array
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var newA = myArray.slice(0);
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// Remove HTML tags
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'<b>A</b>'.replace(/<[^>]+>/gi, '');
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// Reverse a string
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var str = "abc def ghi.";
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str.split('').reverse().join(''); // '.ihg fed cba'
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// Reverse order of words in a string
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str.split(' ').reverse().join(' '); // 'ghi. def abc'
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// Pad Zeros
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// pad(2) => 02
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// pad(10) => 10
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function pad(v){return ('0'+v).substr(-2);}
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// Shuffle array
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function shuffle(ar) { return ar.slice().sort(function() { return Math.random() > 0.5 ? 1 : -1 }) }
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// Check if object is empty
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// is_empty([]) => true
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// is_empty({}) => true
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// is_empty([1]) => false
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function is_empty(obj){if(obj instanceof Array){return obj.length===0;}else if(obj instanceof Object){for(var i in obj)return false;return true;}else return !obj;}
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// Check is it's a scalar object
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// is_scalar(1) => true
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// is_scalar({}) => false
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function is_scalar(obj){return (/string|number|boolean/).test(typeof obj);}
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// Sign of a number
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Math.prototype.sign = function(num){ return (num>0) - (num<0);}
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// Min of an array
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Array.prototype.min = function() { return Math.min.apply(Math, this); };
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//Max of an array
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Array.prototype.max = function() { return Math.max.apply(Math, this); };
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// Shorter if
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// if( variable==1 || variable==2 || variable==3 || variable==15 ) alert('found')
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if ([1,2,3,15].indexOf(variable)!=-1) alert('found')
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// Convert value to boolean
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!!value;
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// Bitwise tricks:
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// Math.floor(4.9); is
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4.9 | 0;
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// Bitwise tricks:
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// Toggle between two values
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x = a ^ b ^ x;
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