$ php -a Interactive mode enabled php > $v1 = "-3.1439253274058"; php > $v2 = (string)(double)$v1; php > echo $v1 == $v2; 1 php > $v1 = "-3.14392532740584"; php > $v1 = "-3.14112532740584"; php > $v2 = (string)(double)$v1; php > echo $v1 == $v2; php > echo $v2; -3.1411253274058 php >