Question

var x = "Hello World {{ 10 + 5 }} {{ 5 - 4 }} ";

x = x.replace( "{{"+/* text */+"}}" , eval( /* text */) );

alert(x); // It's output should be " Hello World 15 1 ";

// How I do this with regEx and eval function;

因为我想制作一个像angular.js

这样的表达式

Answer 1

使用.replace(regExp, function)：

＆＃34; 您可以指定一个函数作为第二个参数。在这种情况下，将在执行匹配后调用该函数。函数的结果（返回值）将用作替换字符串。请注意，如果第一个参数中的正则表达式是全局的，则每次完全匹配都会多次调用该函数。＆＃34;

该函数的参数如下：

Possible name  |  Supplied value
---------------|--------------------------------------------------------
match          |  The matched substring. (Corresponds to $& above.)
               |
p1, p2, ...    |  The nth parenthesized submatch string, provided
               |  the first argument to replace() was a RegExp object.
               |  (Corresponds to $1, $2, etc. above.) For example,
               |  if /(\a+)(\b+)/, was given, p1 is the match for \a+,
               |  and p2 for \b+.
               |
offset         |  The offset of the matched substring within the whole
               |  string being examined. (For example, if the whole
               |  string was 'abcd', and the matched substring was 'bc',
               |  then this argument will be 1.)
               |
string         |  The whole string being examined.

示例：

＆＃13;

var x = "Hello World {{ 10 + 5 }} {{ 5 - 4 }} ";

x = x.replace(/\{\{([^}]+)}}/g, function(_, match) {
  return eval(match); // absolutely unsafe!!!!!
});

console.log(x);

＆＃13;

如何替换这样的所有特殊字符？

1 个答案: