问在JavaScript中自动换行文本

EN

str = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It w as popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.";

str = wordWrap(str, 40);

function wordWrap(str, maxWidth) {
    var newLineStr = "\n"; done = false; res = '';
    while (str.length > maxWidth) {                 
        found = false;
        // Inserts new line at first whitespace of the line
        for (i = maxWidth - 1; i >= 0; i--) {
            if (testWhite(str.charAt(i))) {
                res = res + [str.slice(0, i), newLineStr].join('');
                str = str.slice(i + 1);
                found = true;
                break;
            }
        }
        // Inserts new line at maxWidth position, the word is too long to wrap
        if (!found) {
            res += [str.slice(0, maxWidth), newLineStr].join('');
            str = str.slice(maxWidth);
        }

    }

    return res + str;
}

function testWhite(x) {
    var white = new RegExp(/^\s$/);
    return white.test(x.charAt(0));
};

function wordWrapToStringList (text, maxLength) {
    var result = [], line = [];
    var length = 0;
    text.split(" ").forEach(function(word) {
        if ((length + word.length) >= maxLength) {
            result.push(line.join(" "));
            line = []; length = 0;
        }
        length += word.length + 1;
        line.push(word);
    });
    if (line.length > 0) {
        result.push(line.join(" "));
    }
    return result;
};

wordWrapToStringList(textToWrap, 80).join('<br/>');

> s = "This is a paragraph with several words in it."
'This is a paragraph with several words in it.'
> s.replace(/([\w\s]{10,}?)\s?\b/g, "$1\n")
'This is a \nparagraph \nwith several\nwords in it\n.'

var str = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It w as popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.";

function wordWrap(text,width){
    var re = new RegExp("([\\w\\s]{" + (width - 2) + ",}?\\w)\\s?\\b", "g")
    return text.replace(re,"$1\n")
}

> wordWrap(str,40)
'Lorem Ipsum is simply dummy text of the\nprinting and typesetting industry. Lorem Ipsum has been the industry\'s standard dummy text ever since the 1500s\n, when an unknown printer took a galley of\ntype and scrambled it to make a type specimen\nbook. It has survived not only five centuries\n, but also the leap into electronic typesetting\n, remaining essentially unchanged. It w as popularised in the 1960s with the\nrelease of Letraset sheets containing Lorem\nIpsum passages, and more recently with desktop publishing\nsoftware like Aldus PageMaker including\nversions of Lorem Ipsum.'