常用字符串截取方法总汇,留着备用

 
//js 截取指定字符后面/前面的所有字符串
 
let str = '你还好吗？嗯？我很好！'
			//截取第一个？前面的字符串
			var index = str.indexOf("？")
			var resolve = str.substring(0, index);
			console.log(resolve)
			//你还好吗
 
			//截取第一个？后面的字符串
			var indexs = str.indexOf("？")
			var resolves = str.substring(indexs + 1, str.length);
			console.log(resolves)
			//嗯？我很好！
 
			//截取最后一个？前面的字符串
			let indexss = str.lastIndexOf("？")
			var resolvess = str.substring(0, indexss);
			console.log(resolvess)
			//你还好吗？嗯
 
			//截取最后一个？后面的字符串
			let indexsss = str.lastIndexOf("？")
			var resolvesss = str.substring(indexsss + 1, str.length);
			console.log(resolvesss)
			//我很好！