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highly efficient solution #11

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highly efficient solution #11

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9c12fd7
highly efficient solution
haoel Mar 23, 2016
24a33aa
cover a negtive case : (len < str.length)
haoel Mar 24, 2016
81ca02c
another corner case: if the "ch" is the integer we need cover it to s…
haoel Mar 24, 2016
5ff6fa8
coding sytle
haoel Mar 24, 2016
2fca28d
bug fixing - declare 'pad' variable as a local variable
haoel Mar 24, 2016
1a90e0f
performance test
haoel Mar 25, 2016
6ccfef5
change the typecasting way for 'str' and adjust the order of the code…
haoel Mar 29, 2016
34c1e5c
chore: move benchmark to devdep, add bench script
zhuangya Mar 30, 2016
277ebb3
Merge pull request #1 from zhuangya/minor-change
haoel Mar 30, 2016
4bc455c
remove the comments
haoel Mar 31, 2016
672d883
restore the comments
haoel Apr 1, 2016
64f3b11
removed the commented code
haoel Apr 1, 2016
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15 changes: 9 additions & 6 deletions index.js
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Expand Up @@ -3,15 +3,18 @@ module.exports = leftpad;
function leftpad (str, len, ch) {
str = String(str);
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str = '' + str;
how about?
http://jsperf.com/number-to-string/2
number to string jsperf


var i = -1;

if (!ch && ch !== 0) ch = ' ';

len = len - str.length;
if (len <=0) return str;
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missing whitespace before 0


while (++i < len) {
str = ch + str;
ch = ch + '';
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ch += ''; ?

pad_str = '';
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missing var

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And it's better to use camel-style, let's say var padStr. Maybe pad is another choice.

while (true) {
if (len & 1) pad_str += ch;
len >>= 1
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missing semicolon

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thanks for those comments.

if (len) ch += ch;
else break;
}

return str;
return pad_str + str;
}
5 changes: 4 additions & 1 deletion test.js
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Expand Up @@ -2,9 +2,12 @@ var leftpad = require("./");
var test = require("tape");

test('left pad', function (assert) {
assert.plan(4);
assert.plan(7);
assert.strictEqual(leftpad('foo', 5), ' foo');
assert.strictEqual(leftpad('foobar', 6), 'foobar');
assert.strictEqual(leftpad(1, 2, 0), '01');
assert.strictEqual(leftpad(1, 2, '-'), '-1');
assert.strictEqual(leftpad('foo', 2, ' '), 'foo');
assert.strictEqual(leftpad('foo', -1, ' '), 'foo');
assert.strictEqual(leftpad('foo', 7, 1), '1111foo');
});