JavaScript 中的replace方法

1 第一次发现JavaScript中replace() 方法如果直接用str.replace( " - " , " ! " ) 只会替换第一个匹配的字符.
2 而str.replace( / \ -/ g, " ! " )则可以替换掉全部匹配的字符（g为全局标志）。
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5 replace()
6 The replace() method returns the string that results when you replace text matching its first argument
7 (a regular expression) with the text of the second argument (a string).
8 If the g (global) flag is not set in the regular expression declaration, this method replaces only the first
9 occurrence of the pattern. For example,
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11 var s = " Hello. Regexps are fun. " ;s = s.replace( / \. / , " ! " ); // replace first period with an exclamation pointalert(s);
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13 produces the string “Hello ! Regexps are fun.” Including the g flag will cause the interpreter to
14 perform a global replace, finding and replacing every matching substring. For example,
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16 var s = " Hello. Regexps are fun. " ;s = s.replace( / \. / g, " ! " ); // replace all periods with exclamation pointsalert(s);
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18 yields this result: “Hello ! Regexps are fun ! ”