考虑下面的代码:
var age = 3;
console.log("I'm " + age + " years old!");
除了字符串连接之外，还有其他方法可以将变量的值插入到字符串中吗?
当前回答
当我不知道如何正确地表达，只想快速地得到一个想法时，我就会在很多语言中使用这种模式:
// JavaScript
let stringValue = 'Hello, my name is {name}. You {action} my {relation}.'
.replace(/{name}/g ,'Inigo Montoya')
.replace(/{action}/g ,'killed')
.replace(/{relation}/g,'father')
;
虽然不是特别高效，但我觉得它可读。它总是有效的，而且总是可用的:
' VBScript
dim template = "Hello, my name is {name}. You {action} my {relation}."
dim stringvalue = template
stringValue = replace(stringvalue, "{name}" ,"Luke Skywalker")
stringValue = replace(stringvalue, "{relation}","Father")
stringValue = replace(stringvalue, "{action}" ,"are")
总是
* COBOL
INSPECT stringvalue REPLACING FIRST '{name}' BY 'Grendel Mother'
INSPECT stringvalue REPLACING FIRST '{relation}' BY 'Son shoulder'
INSPECT stringvalue REPLACING FIRST '{action}' BY 'made a gaping mortal-making wound upon.'
其他回答
你可以使用Prototype的模板系统，如果你真的想用大锤敲开一个坚果:
var template = new Template("I'm #{age} years old!");
alert(template.evaluate({age: 21}));
你可以很容易地使用ES6模板字符串，并使用任何可用的transpilar(如babel)编译到ES5。
const age = 3;
console.log(`I'm ${age} years old!`);
http://www.es6fiddle.net/im3c3euc/
let age = 3;
console.log(`I'm ${age} years old!`);
你可以使用反撇号' '和ES6模板字符串
最简单的就是
`my string ${VARIABLE}`
一种效率较低的方法是
function format(str, ...params) {
for(const param of params)
str = str.replace("%", param);
return str;
}
可以和哪个一起使用
format("My % string", "interpolation")
自定义灵活插补:
var sourceElm = document.querySelector('input') // interpolation callback const onInterpolate = s => `<mark>${s}</mark>` // listen to "input" event sourceElm.addEventListener('input', parseInput) // parse on window load parseInput() // input element parser function parseInput(){ var html = interpolate(sourceElm.value, undefined, onInterpolate) sourceElm.nextElementSibling.innerHTML = html; } // the actual interpolation function interpolate(str, interpolator = ["{{", "}}"], cb){ // split by "start" pattern return str.split(interpolator[0]).map((s1, i) => { // first item can be safely ignored if( i == 0 ) return s1; // for each splited part, split again by "end" pattern const s2 = s1.split(interpolator[1]); // is there's no "closing" match to this part, rebuild it if( s1 == s2[0]) return interpolator[0] + s2[0] // if this split's result as multiple items' array, it means the first item is between the patterns if( s2.length > 1 ){ s2[0] = s2[0] ? cb(s2[0]) // replace the array item with whatever : interpolator.join('') // nothing was between the interpolation pattern } return s2.join('') // merge splited array (part2) }).join('') // merge everything } input{ padding:5px; width: 100%; box-sizing: border-box; margin-bottom: 20px; } *{ font: 14px Arial; padding:5px; } <input value="Everything between {{}} is {{processed}}" /> <div></div>
