$speech = "Four score and seven years ago our fathers brought forth, upon this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.";
echo wordwrap($speech, 30);
执行上面的代码，结果是:
Four score and seven years ago our fathers brought forth, upon this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.
原文地址：
原文名：10 Easy Solutions for PHP String Manipulation
作者：W. Jason Gilmore